WAEC Mathematics Past Questions & Answers - Page 59

291.

In the diagram, PR is a tangent to the circle at Q, QT//RS,

A.

40\(^o\)

B.

65\(^o\)

C.

85\(^o\)

D.

95\(^o\)

Correct answer is D

In the diagram,

a = 50\(^o\) (alternate angles)

b\(_1\) + a 35\(^o\) = 180\(^o\) (sum of angles on a straight line)

i.e; b\(_1\) + 50\(^o\) + 35\(^o\)

= 180v

b\(_1\) + 180\(^o\) - 85\(^o\) = 90\(^o\)

But b\(_2\) = \(b_1\) = 95\(^o\) (angles in alternate segement)

<QST = b\(_2\) = 95\(^o\)

292.

Find the value of t in the diagram

A.

63\(^o\)

B.

117\(^o\)

C.

126\(^o\)

D.

234\(^o\)

Correct answer is C

In the diagram,

\(\alpha\) = 180\(^o\) - 177\(^o\) (angles on a straight line)

\(\alpha\) = 63\(^o\)

t = 2 x 63\(^o\) (angle at centre = 2 x angle at circum)

= 126\(^o\)

293.

Find the mean deviation of 20, 30, 25, 40, 35, 50, 45, 40, 20 and 45

A.

8

B.

9

C.

10

D.

12

Correct answer is B

Mean = \(\frac{\sum f x}{\sum f}\)

= \(\frac{350}{10}\)

= 35

= \(\frac{\sum f |d|}{\sum f}\)

= \(\frac{90}{10}\)

= 9

294.

Find the median of 2, 1, 0, 3, 1, 1, 4, 0, 1 and 2

A.

0.0

B.

0.5

C.

1.0

D.

1.5

Correct answer is C

First arrange the numbers in ascending order of magnitude; 0, 0, 1, 1, 1, 1, 2, 2, 3, 4

Counting from the right, the fifth number is 1

Counting from the left, the fifth number is 1

Hence, median = \(frac{1 + 1}{2}\)

= \(\frac{2}{2}\)

= 1

295.

If P and Q are two statements, under what condition would p|q be false?

A.

If p is true and q is true

B.

If p is true and q is false

C.

If p is false and q is false

D.

If p is false and q is true

Correct answer is B

From the truth table above, p \(\to\) q  would be false if p is true and q is false