WAEC Mathematics Past Questions & Answers - Page 101

501.

Which of the following is not a probability of Mary scoring 85% in a mathematics test?

A.

0.15

B.

0.57

C.

0.94

D.

1.01

Correct answer is D

The probability not scoring 85% is = 1 - pro(scoring 85%)

= 1 - \(\frac{85}{100}\) = 1 - 0.85

= 0.15

not scoring would be less than 1

502.

The bearing of Y from X is 060o and the bearing of Z from Y = 060o. Find the bearing of X from Z

A.

300o

B.

240o

C.

180o

D.

120o

Correct answer is B

No explanation has been provided for this answer.

504.

If sin x = \(\frac{5}{13}\) and 0o \(\leq\) x \(\leq\) 90o, find the value of (cos x - tan x)

A.

\(\frac{7}{13}\)

B.

\(\frac{12}{13}\)

C.

\(\frac{79}{156}\)

D.

\(\frac{209}{156}\)

Correct answer is C

Sin x = \(\frac{5}{13}\)

0o \(\leq\) x \(\leq\) 90o, (cos x - tan x)

AC2 = AB2 + BC2

132 = 52 + BC2

169 - 25 + BC2

169 - 25 = BC2

144 = BC2

Cos x = \(\frac{Adj}{Hyp}\) = \(\frac{12}{13}\)

BC = \(\sqrt{144}\)

BC = 12

tan x = \(\frac{opp}{adj} = \frac{5}{12}\)

BC = 12

cos x - tan x = \(\frac{12}{13} - \frac{5}{12}\)

\(\frac{144 - 65}{156} = \frac{79}{156}\)

505.

A cube and cuboid have the same base area. The volume of the cube is 64cm\(^3\) while that of the cuboid is 80cm\(^3\). Find the height of the cuboid

A.

1cm

B.

3cm

C.

5cm

D.

6cm

Correct answer is C

Volume of a cube with side a cm = a\(^3\)

a\(^3\) = 64 \(\implies\) a = 4cm

Base area of a cube = a\(^2\)

= 4\(^2\)

= 16 cm\(^2\)

\(\implies\) Base area of the cuboid = 16 cm\(^2\)

Volume of cuboid = Base area x height

80 = 16 x h

h = \(\frac{80}{16}\)

= 5 cm