2003 - JAMB Mathematics Past Questions and Answers - page 4
31
A
20
B
21
C
15
D
18
correct option: a
\(\begin{array}{c|c} \text{Age in years} & 10 & 20 & 30 & 40 & 50 \\hline \text{frequency} & 3 & 4 & 5 & 6 & 2\end{array}\)
\(\sum f \) = number of people involved in the pollution
\(\sum f\) = 3 + 4 + 5 + 6 + 2 = 20
Users' Answers & Comments\(\sum f \) = number of people involved in the pollution
\(\sum f\) = 3 + 4 + 5 + 6 + 2 = 20
32
Evaluate \(log_{\sqrt{2}}4+log_{\frac{1}{2}}16-log_{4}32\)
A
-5.5
B
-2.5
C
2.5
D
5.5
correct option: c
Note that if we set \(log_{\sqrt{2}}4 = x_{1}, \hspace{1mm}solving\hspace{1mm}gives\hspace{1mm}x_{1}=4\if\hspace{1mm}log_{\frac{1}{2}}16 = x_{2}, \Rightarrow x_{2} = -4\Also \hspace{1mm}for\hspace{1mm}log_{4}32 = x_{3} = 2.5\Combining\hspace{1mm}results,\hspace{1mm}x_{1}+x_{2}+x_{3} = 4+(-4)-2.5=-2.5\)
Note that the solution has been separated to simplify solving difficulty due to different bases.
Users' Answers & CommentsNote that the solution has been separated to simplify solving difficulty due to different bases.
34
In a class of 40 students, 32 offer mathematics, 24 offer Physics, and 4 offer neither Mathematics nor Physics. How many offer both Mat
ematics and Physics?
ematics and Physics?
A
20
B
16
C
8
D
4
correct option: a
Using a venn diagram, let x = number who offer both Maths and Physics. So that (32-x) offer Maths and another (24-x) offer Physics.
(32-x) + (24-x) + (x) + (4 who offer neither) = 40
=> 60 - x = 40
=> -x = -20
Therefore x = 20.
Users' Answers & Comments(32-x) + (24-x) + (x) + (4 who offer neither) = 40
=> 60 - x = 40
=> -x = -20
Therefore x = 20.
35
Find (\(\frac{1}{0.06} \div \frac{1}{0.042}\))-1
A
1.43
B
1.53
C
3.14
D
4.42
correct option: a
Users' Answers & Comments36
A woman buys 270 oranges for N1800.00 and seels at 5 for N40.00. What is her profit?
A
N2,160.00
B
N1, 620.00
C
N630.00
D
N360.00
correct option: d
C.P = N1800
S.P = (270/5) x 400 = N2160.00
Profit = S.P - C.P = N2160 - N1800 = N360.00
Users' Answers & CommentsS.P = (270/5) x 400 = N2160.00
Profit = S.P - C.P = N2160 - N1800 = N360.00
37
Simplify 1 - (7/3 x 5/4) + 2/5
A
-16/15
B
-79/60
C
-37/15
D
-151/60
correct option: b
Users' Answers & Comments38
Simplify (√98 -√50)/√32
A
3
B
1
C
1/2
D
1/4
correct option: c
(√98 - √50)/√32 = √(49x2) - √(25x2) √(16x2)
=> (7√2 - 5√2)/4√2 = 1/2
Users' Answers & Comments=> (7√2 - 5√2)/4√2 = 1/2
39
A cinema halll contains a certain number of people. If 25/2% are children, 95/2% are men and 84 are women, find the number of men in the hall.
A
63
B
84
C
113
D
133
correct option: d
25/2% + 95/2% = 70%
100% - 70% = 30% (i.e women)
=> 30% = 84
1% = 84/30
95/2% = (84/30 x 95/2) = 133.
Users' Answers & Comments100% - 70% = 30% (i.e women)
=> 30% = 84
1% = 84/30
95/2% = (84/30 x 95/2) = 133.
40
If \(\frac{9^{2x-1}}{27^{x+1}} = 1\)find the value of x.
A
8
B
5
C
3
D
2
correct option: b
Cross-multiplying, 92x-1 = 1 x 27x+1
32(2x-1) = 33(x+1)
Solving by equating index: 2(2x-1) = 3(x+1), => x = 5
Users' Answers & Comments32(2x-1) = 33(x+1)
Solving by equating index: 2(2x-1) = 3(x+1), => x = 5