JAMB Mathematics Past Questions & Answers - Page 208

1,036.

If U and V are two distinct fixed points and W is a variable points such that UWV is a right angle, what is the locus of W?

A.

The perpendicular bisector of UV

B.

A circle with UV as radius

C.

A line parallel to the line UV

D.

A circle with the line UV as the diameter

Correct answer is D

No explanation has been provided for this answer.

1,037.

Find the total surface area of solid cone of radius 2\(\sqrt{3}\)cm and slanting side 4\(\sqrt{3}\)

A.

8\(\sqrt{3}\pi \)cm2

B.

24\(\pi \)cm2

C.

15\(\sqrt{3}\pi \)cm2

D.

36\(\pi \)cm2

Correct answer is D

Total surface area of a solid cone

r = 2\(\sqrt{3}\)

= \(\pi r^2\) + \(\pi\)rH

H = 4\(\sqrt{3}\), \(\pi\)r(r + H)

∴ Area = \(\pi\)2\(\sqrt{3}\) [2\(\sqrt{3}\) + 4\(\sqrt{3}\)]

= \(\pi\)2\(\sqrt{3}\)(6\(\sqrt{3}\))

= 12\(\pi\) x 3

= 36\(\pi \)cm2

1,038.

An arc of a circle of radius 6cm is 8cm long. Find the area of the sector

A.

5\(\frac{1}{3}\)cm2

B.

24cm2

C.

36cm2

D.

84cm2

Correct answer is B

Radius of the circle r = 6cm, Length of the arc = 8cm

Area of sector = \(\frac{\theta}{360}\) x \(\pi\)r2........(i)

Length of arc = \(\frac{\theta}{360}\) x 2\(\pi\)r........(ii)

from eqn. (ii) \(\theta\) = \(\frac{240}{\pi}\), subt. for \(\theta\) in eqn (i)

Area x \(\frac{240}{1}\) x \(\frac{1}{360}\) x \(\frac{\pi 6}{1}\)

= 24cm\(^2\)

1,040.

A regular polygon of n sides has 160o as the size of each interior angle. Find n

A.

18

B.

16

C.

14

D.

12

Correct answer is A

No explanation has been provided for this answer.