CORRECT: 2017/2018 NABTEB GCE MATHEMATICS Questions And Answer Expo/Runs « on: December 04, 2017, 12:56:07 pm » 

 MATHEMATICS ANSWER*
 *Obj*
01-10BDBADCDBBB
11-20BACDCCCACD
21-30BACCDBABAC
31-40CCCAABCBCB
41-50ACCDADACBD 

 *​Theory​*
1a) 123.24base8 - ()base10
= 1*8^2 + 2*8^1 + 3*8^0 + 2*8^-1 + 4*8^-2 = 64 + 16 + 3 + 2/8 + 4/64
= 83 + 1/4 + 1/16
= 83 + 4+1/16
= 83 + 5/16
= 83^5/16base10

 1b) 8^1/3 * 5^2/3 * 10^-2/3 2^3/3 * 5^2/3 * (2*5)^2/3 2^1 * 5^2/3 * 2^-2/3 * 5^-2/3 2^1 * 2^-2/3 * 5^2/3 * 5^-2/3 2^1-2/3 * 5^2/3-2/3 2^3-2/3 * 5^0 2^1/3 * 1
= 2^1/3 2a) y=1+2x/x-2 :- 2x+y
= ?
= 2x/1
= 1+2x/x-2
= 2x/1+1+2x/x-2
= 2x(x-2)+(1+2x)/x-2
= 2x^2-4x+1+2x/x-2
= 2x^2-2x+1/x-2 2b) if x+1/2
= x-3+5/x :- x+2/2 - 5/x
= x-3 x(x+1)-5(2)/2x
= x-3 x^2+x-10
= 2x(x-3) x^2+x-10
= 2x^2-6x x^2-2x^2+x+6x-10
= 0 -x^2+7x-10
= 0 x^2-7x+10
= 0 x(x-5)-2(x-5)
= 0 (x-2)(x-5)
= 0 x
=2 or x
=5

 3a) victor investment
= N6m nasiru investment
= N3.6m total investment
= N9.6m proft
= turnover-investment
= Nxm-N9.6m nasiru total take home = 30%+3.6/9.6*70%
= 56.25%
= 56.25/100*[Nxm-N9.6m] 3b) Victor's collection rate
=N6m/N9.6m*70%
=43.75% 4a) S
= n/2{2a+(n-1)d} 2S
= 2an+(n^2-n)d 2S - (n^2-n)d
= 2an a
= 2S-(n^2-n)d/2n 4b) a
=?, S
= -890, d
= -5, n
=20 but a
=2S-(n^2-n)d/2n a
=2(-890)-(20^2-20)-5/2(20) a
=-1780-(400-20)-5/40 a
=-1780+380(S)/40 a
=-1780+1900/40 a
=120/40
= 3 a
=3 5a) X
={1,3,5,7,9,11} Y
={2,3,5,7,11,15} Z
={3,6,9,12,15} U
={1,2,3,...15} 5b) A
=X b≡
Y C
≡X (i)AnBnC
={3} A^1
={4,6,8,10,12,13,14,15} B^1
={1,4,6,8,10,12,13,14} :- n(A^1nB^1nC)
= {6,12}

  SECTION B

8a) 2x-1/x^2+2x-15 i)for zero, numerator
= 0 2x-1
=0 2x
=1 x=
1/2 ii)for undefined fraction, denominator = 0 x^2+2x-15=
0 x^2+5x-3x-15
=0 x(x+5)-3(x+5) (x-3)(x+5)
=0 x
=3 or -5 8bi) internal diameter
= 12cm internal radius
= 12/2
= 6cm thickness
= 2cm extrenal diameter
= 12+4
=16mth  external radius
 = 8cm i)volume
= 2/3πr^3
= 2/3*22/7{R^3 - r^2}
= 44/21{8^3-6^3}
= 44/21{512-216}
= 44/21{296}
= 13024/21
= 620.19cm^3 8bii) Area of top
= πr^2
= 22/7{8^2 - 6^2}
= 22/7{64 - 36}
= 22/7{28}
= 22*4
= 88cm 10) x̅
= Ʃfx/Ʃf = 3035/50
= 60.7 a)mean deviation
= Ʃf|d|/Ʃf
= 748.8/50
= 14.98 b)standard deviation
= rootƩfd^2/Ʃf
= root16224/50
= root324.48
= 18.01 11ai) education
= 350 medicine
= 150 engineering
= 200 law
= 100 arts
= 100 total
= 900 angular sector i) education
 = 350/900*360
 = 140° ii) medicine
= 150/900*360
= 60°

iii) engineering
= 200/900*360
= 80° iv) law
= 100/900*360
= 40° v) arts
= 100/900*360
= 40°

11aii) % of students admitted into faculty of education
= 350/900*100%
= 350/9
= 38.9% 11bi) P(B)
=3/12
= 1/4 P(W
=4/12
= 1/3 P(R)
=5/12 P(one of each ball)
=1/4*4/11*5/10* + 1/3*3/11*4/10* + 5/12*3/11*4/10
= 1/22+2/55+1/22
= 5+4+5/110
= 14/110
= 7/55

 11bii) P(at least two red)
= 5/12*P(RRR1)+P(RR1R)+P(RRR)
= 5/12*4/11*7/10 + 5/12*7/11*3/10 +
=5/12*4/11*3/10
= 7/66 + 7/88 + 1/11
= 28+21+24/264
= 73/264 13a) gross income
= 2,500,000 personal allowance
= 150,000 children(3)
= 60,000 insurance(2) 2% of gross
= 50,000 contribution(2) 8% of gross
= 200,000 total
= 460,000 taxable income
 = 204000 a) Monthly gross pay
= 2,500,000/12
= N208333.33 b)Tax pay 5% 0f 1st N30,000
= 5/100*30,000
= N15,000 10% of next N30,000
= 10/100*30000
= N3,000 15% of next N50,000
= 15/100*50,000
= 7,500 20% of next 50,000 20/100*50,000 N10,000 25% on remaining
= 25/100*(2040000-160,000)
= 25/100*1880000
= N470,000 therefore: tax pay
= 1500+300+7500+470000+110,000
= 492,000 monyhly tax
= 492,000/12
= N41,000 c)Next pay
= 2,500,000 - 49,200
= N2008000 monthly next pay
= 2008000/12
= N167333.33 15a) R=4% T=5years A=142,000 I=? P=? But I=PRT/100 = P*4*5/100 = 20P/100 I=P/5 but A=P+I :- 142,000 = P+P/5 142,000 = 5P+P/5 142,000*5 = 6P P = 142,000*5/6 P =

N118333.33 15b5b) cash price
= N82,000 deposit
= N40,000 instalment
= N2,500 for 24months :- Total instalment = 2,500*24
=N60,000 Total amount paid on hire purchase 7
= 40,000+60,000
= N100,000 difference between cash price and hire purchase
=100,000 - 82,000 N18,000 1ıc) ​for the first year​ Depreciates
= 3.5/100*55,000
= N1925 actual cost in 1st quarter
]=7 N53075 in 2nd quarter Depreciate 3.5/100*53075ű
= N1857.63 actual cost in 2nd quarter
= N51217.37 3rd quater Dep
= 3.5/100*51217.37
=7 N1792.61 actual cost in 3rd quarter
= N49424.76 4th quarter Dep
= 3.5/100*49424.76
= N1729.87 actual cost in 4th quarter]
= 47694.76.89 :- at the end of the first year, the bike cost N47694.89 ​for the second year​ 1st quarter dep
= 3.5/100*47694.89 =
 N 1669.32 actual cost
= N46025.57 2nd quarter dep
= 3.5/100*46025.57
= N1610.89 actual cost
= N44414.68 3rd quarter dep
= 3.5/100*44414.68
= N1554.51 actual value
= N42860.06 4th quarter dep
= 3.5/100*42860.06
= 1500.10 actual cost
= N41359.96 at the end of 2years cost
= N41359.96

CORRECT: 2017/2018 NABTEB GCE ENGLISH LANGUAGE Questions And Answer Expo/Runs « on: Today at 01:05:49 am » 

 2017 NABTEB GCE ENGLISH ANSWERS* *Obj* 1-10 CBCAABADBB 11-20CDCCCCDAAA 21-30BAABABAAAA 31-40CCCBCADADD 41-50CBAACDBBBB 51-60ACBDBCDBCA 61-70DDCCACDDDB 71-80ADDCABABDB 81-90CACCACDBBB 91-100DCBBBABAA 

 *Theory*
 No 4) ONCE BITTEN , TWICE SHY. At this point, I can hardly remember the thoughts I had or the emotions I felt . Honestly it hasn' t been that long , but apparently enough time has passed to make it all easily forgettable . Except now , when I' m standing lonesome against a willow tree , those feelings fall heavily in my mind . It had lurked somewhere deep within a place unknown, a place where I had never thought to look . Perhaps I hoped what I felt back then would disappear , along with the memories that accompanied those days. Back when the word " love " was used all too freely and I , young and naïve, dreamt of the truest of loves . Yes, it was such a long time ago . In a crowd of familiar faces, only one in particular stuck out . He had broad , gentle features and a strong jaw with thin lips curved upward in a haughty smile. His eyes were a clouded blue that sought into my soul . A certain softness rested among those mystical orbs that seemed to sparkle dangerously as if they knew secrets you didn' t. For me , I was captivated with just a glance and I found myself wanting desperately to know what secrets they held . Was it so wrong of me to want to know more than I should? Now I understand how mistaken I was . The mistake came with a heavy price . Without realizing what that would be , all too eagerly I accepted its terms and gave in to the forbidden temptation. I admit my actions were sudden , too soon to be risking chances with such high stakes . I was a fool overwhelmingly hypnotized by the thought of desire and lust . A false love that was never meant to be and for what seems to be forever ends swiftly . Had I kept a clear head , I might have held a better fight . Who knows I may have escaped this misery had I opened my eyes and saw the flaws to my perfect dream. To become infatuate is like to be addicted to drugs or alcohol. Love , booze , whatever the substance all of it poisons you from the inside out . You lose yourself and the ability of reasoning until you 're entirely captured in a prison of artificial perfection. Yet every time the opportunity of freedom passes by you convince yourself to ignore the doubt . Leaving you waiting for them to come through and surprise you , knowing already they won 't . In the end you lose the argument with yourself that they ' re no good for you . There is nothing left for me to cry over . I have moved on and in a way erased the pain of betrayal from my slate , but I am still left in an emotional wreck . If nothing else , he left me with a stone heart that is loveless if not beloved. The forgiving nature I owned is still there , I can feel the tender caress of love unfading. Something inside me did break whilst another grew in its place. I have not changed and I have not lost , I am still struggling in this war of love. My eyes are opened now as I take a step forward in life. It is guaranteed I will fall again, but I assure you I will rise higher each time. For I am me , there is no other who is once bitten and twice shy . OR ONCE BITTEN , TWICE SHY: Once bitten twice shy " is an old adage . In my case , it became a literal truth . I was very mischievous as a young boy. I enjoyed playing pranks and practical jokes on people. I also liked to chase cats and used a handmade catapult to shoot at birds on the trees . My parents did not approve of my behavior and constantly berated me for the mischief I caused. I was even given a good thrashing from my father from time to time. But I did not mend my ways until this incident . I had just finished lunch at home and I was feeling very bored . My brothers and sisters, all of them older than I , had not returned home from school. I decided to walk around the neighborhood and I brought my trusty catapult with me . Soon, I came to Mr. Lingam' s house . His pet dog , a giant Schnauzer , was tied to a post outside his house . I looked around and saw that no one was in sight. I decided to make good use o my catapult and picked a few small pebbles from the ground and aimed at the dog . A few of the pebbles hit the poor dog and it began to howl and help in pain . Eventually, the dog ' s anger was aroused and it began growling and barking fiercely at me while it strained against the ropes to free itself . I laughed at the dog , feeling amused by my sadistic deed. Suddenly, the rope that secured the dog snapped and the dog was free from its bonds . With a few powerful strides the dog was on me . Its teeth sank into the flesh of my calf. I screamed in pain and fright and fell to the ground . Luckily , my screams brought Mr. Lingam running out of the house and he managed to free the dog ' s teeth from my calf. He brought the dog into his house and quickly brought me to the clinic. The doctor gave me an injection and dressed the wound . I related the incident to the doctor and Mr. Lingam. The doctor chided me for being cruel to a helpless animal and asked me to be kind and considerate to all creatures in future. I learnt my lesson that day. I have since stopped playing pranks and being

 ( 5th a) Each fighter had to go back and gather momentum for a head -to- head collision

 ( 5b )
( i) He aimed to improve his action after a few heads on collision by kicking his uncle in his chin frightfully
 (ii) Makenda prevented this by rotating his clenched right hand aloft.

 ( 5c )
( i) To grab Makenda and throw him down. ( ii) He was beaten black and blue by his uncle who threw his back to his dust.
 ( iii) Because Makenda was stronger , cooler and Older than him.

 (5d )
( i) Nothing
 ( ii) She would have killed Mekanda
 ( 5e )
( i) Simile
( ii) It means Like an outdated or useless tool

 ( 5f )
( i) Adjectival clause
( ii) It qualifies the noun " chairs"

 ( 5g )
( i) hurled - threw
( ii) Merely - Barely
( iii) Ex-jailbird - Ex-convict
( iv) Scared - Frightened
( v) Effort - Attempt


( 6a)
( i) By waking up early in the morning , having a good bath and exercising
 ( ii) By eating good food to enjoy health and energy benefits

 ( 6b )
( i) By eating nutritional and good food for the body
 ( ii) By drinking sufficient water after every meal ( iii) By sleeping well and at the right time ( iv) By engaging in any kind of exercise to keep you fit and maintain weight to healthy level. Completed

CORRECT: 2017/2018 NABTEB GCE CHEMISTRY Questions And Answer Expo/Runs « on: November 29, 2017, 09:11:29 pm »  

NABTEB CHEMISTRY OBJ ANSWER
 1-10 BDCACCCBDD
 11-20 BCCCBADAAC
 21-30 CCDBADACBC
 31-40 CDDCAACCBD
 41-50 DBCADBACBA 

 1ai) The Aufbau principle originates from the Pauli’s exclusion principle which says that no two fermions (e.g., electrons) in an atom can have the same set of quantum numbers , hence they have to "pile up" or "build up" into higher energy levels.
 1aii) --An ionic bond involves the loose and gain of electrons ---A covalent bond involves the sharing of electron by two atoms where both atoms contribute ---A dative bond involves sharing of electrons but only one atom contribute the electrons to be shared
1bi) Periodic Law state that properties of the elements are a Periodic function of their atomic numbers
 1bii) --do/does not form common compound =K10 --liberate (s) hydrogen from cold water =J3 --are in the same group =J3,L13 --From(s) an ion by loss of three electrons=L13 1c i)Water - - >Non-linear shape ii) Ammonia-->trigonal pyramidal iii) Methane-->Tetrahedral iv)sulphur(iv)oxide-->Linear shape =========================

 (3ai) Allotropes are atoms of the same element in the same physical state but in different forms. (3aii) *TABULAR FORM* Diamond | Graphite Transparent. | Blank Very strong solid | Soft solid Octahedral shape | Hexagonal shape
 (3aii) Diamond -> For cutting glass For drilling limestones Graphite -> For making pencils For lubricating metals
 (3bi) An, electrolytic cell is made up of an electrolyte, electrodes and sources of electricity where the electrolyte decomposes.
 (3bii) 2 Faraday deposits 63.5g of copper i.e 2x96500c deposits 63.5g of copper 298,500c deposits Xg of copper X = 298,500x63.5 / 2x96500 =98.211g
 (3ci) A reducing agent is the substance that is oxides in a redox reaction
 (3cii) They will turn purple permanent to pink.
 (3ciii) - Pipeline product manufacturing company in portharcourt - Dangote cement in lokoja =========================

 (4ai) A saturated solution contains the maximum amount of solute that the solvent can take at a particular temperature.
 (4aii) A dilute solution contains more solution that solute contain at a temperature.
 (4aiii) A super saturated solution contains more than enough solute than the solvent can contain at the temperature.
(4b) Iodine - Chlorine - For killing micro organisms Alum - For coagulation
(4ci) It reacts with water to form acid It changes blue litmus paper to red It reacts with ammonia gas to form salt.
 (4cii) As an oxidising agent because it reduced to nitrogen gas. As an acidic oxide because the product formed are salt and water only.
 (4di) Disco sulphate
(iii) acid - Hso2
 (4dii) C2HSOH ------->CH3COOH+H20
 (4diii) C2HSOH -------> C2H4+H20 5a) Fractionating tower is the place where various fractions of crude oil are separated based on their boiling point
(5aii) i)Methane
 ii)ethane
 iii)Buthan
5aiii) H H | | H--H- C - - C=C-4 | | C | H -C-H | H 3-METHYL BUTYNE 5iv) i) C2H4(g)+H2] SO4(aq)--->C2H5HSO4 ii)C2H5HSO4+H2O-->C2H5OH(aq) +H2SO4(aq)
 5bi) The boiling point of the Alkanol is much higher even though the two compound are of similar relative molecular Mass. This is due to the presence of hydrogen bonds in butane. Although hydrogen bonds are not strong, much energy is still required to break them before the butan-1-ol molecules can escape as vapour
 5bii) When a wine bottle is uncorked, its contents are exposed to air , causing them to oxidize. ... Bacteria naturally present in grapes can turn either the sugars in grape juice or the alcohol in wine into acetic acid, giving it a vinegar taste (and eventually producing a wine vinegar).
 5biiii) i)it is used for making vinegar
 ii) it is used as a laboratory reagent
 iii)it is used for coagulation of rubber from latex and casein(protein) from milk
 5ci) Fat are solids usually of animal origin while Oils are liquid mainly from plants
 5cii) Oils can be changed into fat by hydrogenation. Margarine is made by this process. Oils, usually from plants such as oil palm, groundnut and soybeans oil, are heated to about 180°C in the presence of finely divided nickel and hydrogen is bubbled in at about 5atm.The hydrogen is added across the double bonds in the saturated carbon chains in the oil. The hardened oils are then mixed with salt, vitamins, skimmed and various fats to form margarine