WAEC Past Questions and Answers - Page 2254

11,266.

A prerequisite for orderliness is

A.

Humility

B.

Morality

C.

Hard work

D.

Politeness

Correct answer is D

Orderliness is the art by which things are arranged in a proper, neat and systematic manner.
Politeness is the practical application of good manners or etiquette so as not to offend others.

11,267.

John was facing S35°E. If he turned 90° in the anticlockwise direction, find his new direction.

A.

S55°E.

B.

S35°W.

C.

N55°E.

D.

N35°W.

Correct answer is C

Consider |NS|
θ = 180° - (90° + 35°) (sum of angles on a straight line is 180°)
= 180° - 90° - 35°
= 90° - 35°
= 55°
∴ His new bearing is N55°E.

11,268.

A number is chosen at random from 40 and 50 inclusive. Find the probability that the number is prime.

A.

\(\frac{8}{11}\)

B.

\(\frac{3}{11}\)

C.

\(\frac{4}{11}\)

D.

\(\frac{5}{11}\)

Correct answer is B

Total numbers from 40 to 50 inclusive = 11 (40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50).

Prime numbers between 40 and 50 (inclusive) are 41, 43, and 47.

There are 3 prime numbers in this range.

therefore, Pr(prime numbers) = \(\frac{3}{11}\)

11,269.

Arrange the following in ascending order of magnitude \(110_{two}, 31_{eight}, 42_{five}\)

A.

\(110_{two}, 31_{five}, 42_{eight}\)

B.

\(42_{five}, 110_{two}, 31_{eight}\)

C.

\(42_{five}, 31_{eight}, 110_{two}\)

D.

\(110_{two}, 42_{five}, 31_{eight}\)

Correct answer is D

Converting each number to base 10
\(110_{two} = 1 × 2^2 + 1 × 2^1 + 0 × 2^0\)
= 1 × 4 + 1 × 2 + 0 × 1
= 4 + 2 + 0
= \(6_{ten}\)
\(31_{eight} = 3 × 8^1 + 1 × 8^0\)
= 3 × 8 + 1 × 1
= 24 + 1
= \(25_{ten}\)
\(42_{five} = 4 × 5^1 + 2 × 5^0\)
= 4 × 5 + 2 × 1
= 20 + 2
= \(22_{ten}\)
Hence, \(31_{eight} > 42_{five} > 110_{two}\)
In ascending order, \(110_{two}, 42_{five}, 31_{eight}\)

11,270.

An empty cylindrical tank is 140 cm in diameter. If 200 litres of water was poured into the tank. Calculate, correct to the nearest centimeter, the height of the water in the tank. (\(Take \pi = \frac{22}{7})\)
 

A.

91cm

B.

7cm

C.

13cm

D.

57cm

Correct answer is C

given that diameter = 140cm ⇒radius = 70cm, volume of cylinder = 200litres = \(200,000cm^3\)

volume of cylinder = base area times height = \(\pi r^2h\)

\( 200,000cm^3 = \frac{22}{7} \times 70 \times 70 \times h\)

\(200,000 = \frac{107,800h}{7}\)

cross multiply

1,400,000 = 107,800h 

\( h = \frac{1,400,000}{107,800}\)

   = 13cm (to the nearest cm).