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JAMB Mathematics Past Questions & Answers - Page 201

1,001.

The ratio of the length of two similar rectangular blocks is 2 : 3. If the volume of the larger block is 351cm $^3$ , then the volume of the other block is?

234.00 cm³

526.50 cm³

166.00 cm³

687cm³

View answer & explanation

Correct answer is A

Let x represent total vol. 2 : 3 = 2 + 3 = 5

$\frac{3}{5}$ x = 351

x = $\frac{351 \times 5}{3}$

= 585

Volume of smaller block = $\frac{2}{5}$ x 585

= 234.00cm $^3$

1,002.

If two fair coins are tossed, what is the probability of getting at least one head?

$\frac{1}{4}$

$\frac{1}{2}$

$\frac{43}{78}$

$\frac{3}{4}$

View answer & explanation

Correct answer is E

Prob. of getting at least one head

Prob. of getting one head + prob. of getting 2 heads

= $\frac{1}{4}$ + $\frac{2}{4}$

= $\frac{3}{4}$

1,003.

If the hypotenuse of right angled isosceles triangle is 2, what is the length of each of the other sides?

$\sqrt{2}$

$\frac{1}{2}$

2 - 1

View answer & explanation

Correct answer is A

45^o = $\frac{x}{2}$ , Since 45^o = $\frac{1}{\sqrt{2}}$

x = 2 x $\frac{1}{\sqrt{2}}$

= $\frac{2\sqrt{2}}{2}$

= $\sqrt{2}$

1,004.

The number of goals scored by a football team in 20 matches is shown below
$\begin{array}{c|c} \text{No. of goals} & 0 & 1 & 2 & 3 & 4 & 5 \\ \hline \text{No. of matches} & 3 & 5 & 7 & 3 & 1 & 0 \end{array}$
What are the values of the mean and the mode respectively?

(1.75, 5)

(1.75, 2)

(1.75, 1)

(65, 74)

View answer & explanation

Correct answer is B

$\begin{array}{c|c}x & f & fx\\ \hline 0 & 3 & 0\\ 1 & 5 & 5\\ 2 & 7 & 14\\ 3 & 4 & 12\\4 & 1 & 4\\5 & 0 & 0\end{array}$
$\sum{f}$ = 20

$\sum fx$ = 35

Mean = $\frac{\sum fx}{\sum f}$

= $\frac{35}{20}$

= $\frac{7}{4}$

= 1.75

Mode = 2

= 1.75, 2