JAMB Mathematics Past Questions & Answers - Page 72

356.

Divide the L.C.M of 48, 64 and 80 by their H.C.F

A.

20

B.

30

C.

48

D.

60

Correct answer is D

No explanation has been provided for this answer.

357.

A room is 12m long, 9m wide and 8m high. Find the cosine of the angle which a diagonal of the room makes with the floor of the room.

A.

\(\frac{15}{17}\)

B.

\(\frac{9}{17}\)

C.

\(\frac{8}{15}\)

D.

\(\frac{12}{17}\)

Correct answer is A

Given length of the room = 12m; breadth = 9m and height = 8m.

The room is a cuboid in shape, therefore the length of the diagonal = \(\sqrt{l^2 + b^2 + h^2}\)

= \(\sqrt{12^2 + 9^2 + 8^2}\)

=\(\sqrt{289}\)

= 17m.

The diagonal makes an angle with the diagonal of the floor: \(\sqrt{12^2 + 9^2}\)

= \(\sqrt{225}\)

= 15m

The cosine of the angle that the diagonal makes with the floor (\(\theta\)) = \(\frac{15}{17}\).

 

359.

\(\frac{0.00256 \times 0.0064}{0.025 \times 0.08}\)

A.

8.8 x 10\(^{-1}\)

B.

8.8 x 10\(^{-2}\)

C.

8.2 x 10\(^{-3}\)

D.

8.8 x 10\(^{3}\)

Correct answer is C

No explanation has been provided for this answer.

360.

How many times, correct to the nearest whole number, will a man run round a circular track of diameter 100m to cover a distance of 1000m?

A.

3

B.

4

C.

5

D.

6

Correct answer is A

In terms of distance, a circle has a total distance or perimeter of 2πr or πd

  Where r is radius and d is the diameter

  So perimeter = \(\frac{22}{7}\) x 100

  = 314.2857m

  To cover a distance of 1000m, he is going to round the circular track for \(\frac{1000}{314.2857}\) = 3.18

\(\approxeq\) 3 (to the nearest whole number)