2008 - JAMB Mathematics Past Questions and Answers - page 1
1
A
1110112
B
1101102
C
1010112
D
1010102
2
If 125x = 2010 find x
A
2
B
3
C
4
D
5
correct option: b
125x = 20
1xX2 + 2xX1 + 5xX0 = 20
X2 + 2X + 5 = 20
X2 + 2X - 15 = 0
(X + 5)( X - 3) = 0
X + 5 implies X = -5
X - 3 implies X = 3
But X cannot be negative
∴X = 3
Users' Answers & Comments1xX2 + 2xX1 + 5xX0 = 20
X2 + 2X + 5 = 20
X2 + 2X - 15 = 0
(X + 5)( X - 3) = 0
X + 5 implies X = -5
X - 3 implies X = 3
But X cannot be negative
∴X = 3
3
Evaluate \(\frac{\left(\frac{3}{8}\div\frac{1}{2}+\frac{1}{2}\right)}{\left(\frac{1}{8}\times\frac{2}{3}+\frac{1}{3}\right)}\)
A
1/4
B
1/3
C
1/2
D
1
correct option: d
\(\frac{\left(\frac{3}{8}\div\frac{1}{2}+\frac{1}{2}\right)}{\left(\frac{1}{8}\times\frac{2}{3}+\frac{1}{3}\right)}\\
=\frac{\left(\frac{3}{8}\times\frac{2}{1}+\frac{1}{2}\right)}{\left(\frac{1}{8}\times\frac{2}{3}+\frac{1}{3}\right)}\\
=\frac{\left(\frac{3}{4}-\frac{1}{3}\right)}{\left(\frac{1}{12}+\frac{1}{3}\right)}\\
=\left(\frac{9-4}{12}\right)\div\left(\frac{1+4}{12}\right)\\
=\left(\frac{5}{12}\right)\div\left(\frac{5}{12}\right)\\
=\frac{5}{12}\times\frac{12}{5}\\
=1\)
Users' Answers & Comments4
Express 1223456 to 3 significant figures
A
123000
B
124000
C
125000
D
126000
correct option: a
Users' Answers & Comments5
calculate the simple interest on N6,500 for 8 years at 5% per annum.
A
N3,000
B
N600
C
N300
D
N150
correct option: a
\(I = \frac{P \times T \times R}{100}\\
=\frac{7500 \times 8 \times 5}{100}\\
=N3000\)
Users' Answers & Comments6
The cost of kerosine per liter increase from N60 to N85. What is the percentage rate of increase?
A
42%
B
41%
C
40%
D
25%
correct option: a
N85 - N60 = N25 increase
∴percentage increase = \(\frac{25}{60}\times \frac{100}{1}\=\frac{125}{3}\=41.67%\\ =42%\)
Users' Answers & Comments∴percentage increase = \(\frac{25}{60}\times \frac{100}{1}\=\frac{125}{3}\=41.67%\\ =42%\)
7
simplify \(16^{\frac{-1}{2}}\times 4^{\frac{-1}{2}} \times 27^{\frac{1}{3}}\)
A
3/8
B
2/3
C
3/4
D
3/2
correct option: a
\(16^{\frac{-1}{2}}\times 4^{\frac{-1}{2}} \times 27^{\frac{1}{3}}\\
=\frac{1}{16^{\frac{1}{2}}}\times \frac{1}{4^{\frac{1}{2}}}\times 27^{\frac{1}{3}}\\
=\frac{1}{\sqrt{16}} \times \frac{1}{\sqrt{4}} \times sqrt[3]{27}\\
=\frac{1}{4} \times \frac{1}{2} \times \frac{3}{1}\\
= \frac{3}{8}\)
Users' Answers & Comments8
If logx1/264 = 3, find the value of x
A
4
B
16
C
32
D
64
correct option: b
If logx1/264 = 3
(X 1/2)3 = 64
(X 1/2)3 = 4 3
X 1/2 = 4
X = 42
X = 16
Users' Answers & Comments(X 1/2)3 = 64
(X 1/2)3 = 4 3
X 1/2 = 4
X = 42
X = 16
9
If \(\frac{1+\sqrt{2}}{1-\sqrt{2}}\) is expressed in the form of x+y√2 find the values of x and y
A
(-3, -2)
B
(-2, 3)
C
(3,2)
D
(2,-3)
correct option: a
\(\frac{1+\sqrt{2}}{1-\sqrt{2}} \times \frac{1+\sqrt{2}}{1+\sqrt{2}}\\
=\frac{1+(1+\sqrt{2})+\sqrt{2}(1+\sqrt{2})}{1^2 - (\sqrt{2})^2}\\
=\frac{(1+\sqrt{2}+\sqrt{2}+2)}{1-2}\\
=\frac{3+2\sqrt{2}}{-1}\\
=-3-2\sqrt{2}\\
∴X and Y = -3 and -2\)
Users' Answers & Comments10
If X = {n2 + 1:n = 0,2,3} and Y = {n+1:n=2,3,5}, find X∩Y.
A
{1,3}
B
{5,10}
C
∅
D
{4,6}