2016 - JAMB Mathematics Past Questions and Answers - page 3
21
Simplify \(\frac{0.026 \times 0.36}{0.69}\). Leave your answer in standard form
A
1.36 x 10-4
B
1.36 x 10-3
C
1.36 x 10-1
D
1.36 x 10-2
correct option: d
\(\frac{0.026 \times 0.36}{0.69}\) = \(\frac{26 \times 10^-3 \times 36 \times 10^-2}{69 \times 10^-2}\)
= 0.01356 = 1.36 x 10-2
Users' Answers & Comments= 0.01356 = 1.36 x 10-2
22
A number of pencils were shared out among Bisi, Sola and Tunde in the ratio of 2:3:5 respectively. If Bisi got 5, how many were shared out?
A
15
B
25
C
30
D
50
correct option: b
Let x represent total number of pencils shared
B : S : T
2 : 3 : 5
2+3+5 = 10
\(\frac{2}{10}\) x x = 5
\(\frac{2x}{10}\) = 5
2x = 50
x = 25
Users' Answers & CommentsB : S : T
2 : 3 : 5
2+3+5 = 10
\(\frac{2}{10}\) x x = 5
\(\frac{2x}{10}\) = 5
2x = 50
x = 25
23
Calculate the perimeter of a sector of a circle of raduis 9cm and angle 36o.
A
18cm
B
(18 + \(\frac{9\pi}{5}\))cm
C
(9 + \(\frac{9\pi}{5}\))cm
D
\(\frac{9\pi}{5}\)cm
correct option: b
Perimeter = 2r + \(\frac{\theta}{360}\) x 2\(\pi\)r
2(9) + \(\frac{36}{360}\) x 2 x \(\pi\) x 9 = 18 + \(\frac{9\pi}{5}\)
Users' Answers & Comments2(9) + \(\frac{36}{360}\) x 2 x \(\pi\) x 9 = 18 + \(\frac{9\pi}{5}\)
24
Evaluate \(\frac{27^\frac{1}{3} - 8^\frac{2}{3}}{16^\frac{2}{4} \times 2}\)
A
\(\frac{23}{5}\)
B
-\(\frac{23}{5}\)
C
\(\frac{1}{8}\)
D
\(\frac{21}{7}\)
correct option: c
\(\frac{27^\frac{1}{3} - 8^\frac{2}{3}}{16^\frac{2}{4} \times 2}\)
\(\frac{27^\frac{1}{3} - 8^\frac{2}{3}}{16^\frac{2}{4} \times 2}\) = \(\frac{3\sqrt{27} - 3\sqrt{8}^2}{\sqrt{16} \times 2}\)
\(\frac{3 - 4}{4 \times 2}\)
= \(\frac{-1}{8}\)
Users' Answers & Comments\(\frac{27^\frac{1}{3} - 8^\frac{2}{3}}{16^\frac{2}{4} \times 2}\) = \(\frac{3\sqrt{27} - 3\sqrt{8}^2}{\sqrt{16} \times 2}\)
\(\frac{3 - 4}{4 \times 2}\)
= \(\frac{-1}{8}\)
25
\(\begin{array}{c|c}
Scores & 3 & 6 & 5 & 2 \\ \hline
Frequency & 2 & 3 & 4 & 6
\end{array}\)
From the table above, find the median
Scores & 3 & 6 & 5 & 2 \\ \hline
Frequency & 2 & 3 & 4 & 6
\end{array}\)
From the table above, find the median
A
3
B
5
C
4
D
6
correct option: c
Mean = \(\frac{(2 \times 3) + (3 \times 6) + (4 \times 5) + (2 \times 6)}{2 + 3 + 4 + 6}\)
= \(\frac{6 + 18 + 20 + 12}{15}\) = \(\frac{56}{15}\)
= 3.73
Users' Answers & Comments= \(\frac{6 + 18 + 20 + 12}{15}\) = \(\frac{56}{15}\)
= 3.73
26
Find \(\frac{dy}{dx}\), if y = \(\frac{2}{3}\) X3 - \(\frac{4}{x}\)
A
3x2 - \(\frac{4}{x}\)
B
2x2 +\(\frac{4}{x^2}\)
C
3x2 + \(\frac{4}{x^2}\)
D
2x2 - \(\frac{4}{x}\)
correct option: b
y = \(\frac{2}{3}\)x3 - \(\frac{4}{x}\)
\(\frac{dy}{dx}\) = 2x2 - Lx-2 = 2x2 + \(\frac{4}{x^2}\)
Users' Answers & Comments\(\frac{dy}{dx}\) = 2x2 - Lx-2 = 2x2 + \(\frac{4}{x^2}\)
27
Evaluate \(\frac{0.8 \times 0.43 \times 0.031}{0.05 \times 0.72 \times 0.021}\). Correct to four significant figures.
A
14.09
B
14.1
C
14.12
D
14.11
correct option: d
\(\frac{0.8 \times 0.43 \times 0.031}{0.05 \times 0.72 \times 0.021}\) x \(\frac{10}{10}\) = 14.11
Users' Answers & Comments28
An arc subtends an angle of 30o at the centre of a circle radius 12cm. Calculate the length of the arc.
A
6\(\pi\)cm
B
2\(\pi\)cm
C
3\(\pi\)cm
D
9\(\pi\)cm
correct option: b
Length or arc = \(\frac{\theta}{360}\) x 2\(\pi\)r
= \(\frac{30}{360}\) x 2 x \(\frac{22}{7}\) x 12
= \(\frac{1}{12}\) x 2 x \(\pi\) x 2 = 2\(\pi\)cm
Users' Answers & Comments= \(\frac{30}{360}\) x 2 x \(\frac{22}{7}\) x 12
= \(\frac{1}{12}\) x 2 x \(\pi\) x 2 = 2\(\pi\)cm
29
Evaluate \(\int\limits_0^\frac{\pi}{2}\) sin xdx
A
2
B
-1
C
1
D
-2
correct option: c
\(\int\limits_0^\frac{\pi}{2}\) sin xdx = -cosx|\(\frac{\pi}{2}\)
= -(cos\(\frac{\pi}{2}\) - cos0) = -(0-1) = 1
Users' Answers & Comments= -(cos\(\frac{\pi}{2}\) - cos0) = -(0-1) = 1
30
An arc of the length 16\(\pi\)cm subtends an angle of 80o at the centre of the circle. Find the radius of the circle.
A
24cm
B
28cm
C
36cm
D
32cm
correct option: c
L = \(\frac{\theta}{360}\) x 2\(\pi\)r
16\(\pi\) = \(\frac{80}{360}\) x 2\(\pi\)r
\(\frac{16\pi \times 360}{80 \times 2\pi}\) = r
r = 36cm
Users' Answers & Comments16\(\pi\) = \(\frac{80}{360}\) x 2\(\pi\)r
\(\frac{16\pi \times 360}{80 \times 2\pi}\) = r
r = 36cm