WAEC Past Questions and Answers - Page 3727

18,631.

A train moving at a uniform speed covers 36km in 21 minutes. How long does it take to cover 60km?

A.

35 mins

B.

40 mins

C.

45 mins

D.

90 mins

Correct answer is A

Since 36km in 21 minutes
1km in \(\frac{21}{36}\)minutes
60km in \(\left(\frac{21}{36}\times 60\right)\)minutes = \(\frac{70}{2}\)min
= 35 mins

18,632.

P = {3, 9, 11, 13} and Q = {3, 7, 9, 15} are subset of the universal set ξ = {1, 3, 7, 9, 11, 13, 15} find PI ∩ QI

A.

{3, 9}

B.

{5, 7, 9}

C.

{1}

D.

{1, 11}

Correct answer is C

PI = {1, 7, 15} ; QI = {1, 13, 11}
PI ∩ QI = {1}

18,633.

which of the following statements describes the locus of a point R which moves in a plane such that its equidistant from two intersecting lines?

A.

the bisector of the angle formed by the lines

B.

the point of intersection of the two lines

C.

A cone, with two intersecting lines as slant height

D.

A circle, with the point of intersection of the two lines as the center

Correct answer is A

No explanation has been provided for this answer.

18,634.

An arc of a circle of radius 14cm subtends angle 300o at the center. Find the perimeter of the sector formed by the arc

A.

14.67cm

B.

42.67cm

C.

101.33cm

D.

543.33cm

Correct answer is C

The perimeter of the sector \(=2r+\frac{\theta}{360}\times 2\pi r \\
\Rightarrow 28 + \frac{300}{360} \times \frac{2}{1} \times \frac{22}{7}\times \frac{14}{1} = \frac{220}{3}+28\\
73.133+28=101.33cm\)

18,635.

What is the total surface area of a closed cylinder of height 10cm and diameter 7cm? [Take \(\pi = \frac{22}{7}\)]

A.

77cm2

B.

227cm2

C.

297cm2

D.

374cm2

Correct answer is C

T.S.A of s closed cylinder = \(2\pi r(r+h)\\
=\frac{2}{1}\times \frac{22}{7} \times \frac{7}{2}\left(\frac{7}{2}+\frac{10}{1}\right)=\frac{22}{1}\left(\frac{27}{2}\right)=27\times 11=297cm^2\)