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JAMB Mathematics Past Questions & Answers - Page 185

921.

PQR is the diagram of a semicircle RSP with centre at Q and radius of length 3.5cm. If QPT = 60^o. Find the perimeter of the figure PTRS. $\pi$ = $\frac{22}{7}$

25cm

18cm

36cm

29cm

25.5cm

View answer & explanation

Correct answer is A

Circumference of PRS = $\frac{\pi}{2}$ = $\frac{22}{7}$ x $\frac{7}{1}$ x $\frac{1}{2}$

= 11cm

Side PT = 7cm, Side TR = 7cm

Perimeter(PTRS) = 11cm + 7cm + 7cm

= 25cm

922.

Simplify $\sqrt[3]{\frac{27a^{-9}}{8}}$ .

$\frac{9a^2}{2a^3}$

$\frac{3}{2a^3}$

$\frac{2}{3a^2}$

$\frac{3a^2}{2}$

View answer & explanation

Correct answer is B

$\sqrt[3]{\frac{27a ^{-9}}{8}}$ = $\frac{3a^{-3}}{2}$

= $\frac{3}{2}$ x $\frac{1}{a^3}$

= $\frac{3}{2a^3}$

923.

On a square paper of length 2.524375cm is inscribed square diagram of length 0.524375cm. Find the area of the paper not covered by the diagram. correct to 3 significant figures.

6.00cm²

6.10cm²

6cmv

6.09cm²

4.00cm²

View answer & explanation

Correct answer is B

Area of the paper = area of square = L x B or S²

where s = S x k

Area of the paper = (2.524)²

area of the diagram = (0.524)²

area not covered = (2.524)² - (0.524)²

= 6.370576 - 0.274576

= 6.096

= 6.10cm² (2 s.f)

924.

In a sample survey of a University Community, the following table shows the percentage distribution of the number of members per house hold
$\begin{array}{c|c} \text{No. of members per household} & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & \text{Total} \\ \hline \text{No. of households} & 3 & 12 & 15 & 28 & 21 & 10 & 7 & 4 & 100\end{array}$

What is the median?

4.5

None

View answer & explanation

Correct answer is A

$\begin{array}{c|c} x & f \\\hline 1 & 3\\ 2 & 13\\3 & 15\\ 4 & 28\\ 5 & 21\\ 6 & 10\\ 7 & 7\\ 8 & 4\end{array}$

Median is half of total frequency = 50th term

4 falls in the range = 4