JAMB Mathematics Past Questions & Answers - Page 206

1,026.

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?

A.

234.00 cm3

B.

526.50 cm3

C.

166.00 cm3

D.

687cm3

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\(^3\)

1,027.

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

A.

\(\frac{1}{4}\)

B.

\(\frac{1}{2}\)

C.

1

D.

\(\frac{43}{78}\)

E.

\(\frac{3}{4}\)

Correct answer is E

Prob. of getting at least one head

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

= \(\frac{1}{4}\) + \(\frac{2}{4}\)

= \(\frac{3}{4}\)

1,028.

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

A.

\(\sqrt{2}\)

B.

\(\frac{1}{2}\)

C.

22

D.

1

E.

2 - 1

Correct answer is A

45o = \(\frac{x}{2}\), Since 45o = \(\frac{1}{\sqrt{2}}\)

x = 2 x \(\frac{1}{\sqrt{2}}\)

= \(\frac{2\sqrt{2}}{2}\)

= \(\sqrt{2}\)

1,029.

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?

A.

(1.75, 5)

B.

(1.75, 2)

C.

(1.75, 1)

D.

(65, 74)

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