Year : 
1991
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

41 - 50 of 50 Questions

# Question Ans
41.

Mrs. Jones is expecting a baby. The probability that it will be a boy is 1/2 and probability that the baby will have blue eyes is 1/4. What is the probability that she will have a blue-eyed boy?

A. 1/8

B. 1/4

C. 3/8

D. 1/2

E. 3/4

Detailed Solution

(1/2)(1/4) = 1/8
42.

Which of the following about a rhombus may not be true?

A. The diagonals are equal

B. The diagonals bisect the angles through which they pass

C. the diagonals bisect each other

D. The adjacent sides are equal

E. Opposite angles are equal

A

43.

The angles of a pentagon are x°, 2x°, (x + 60)°, (x + 10)°, (x -10)°. Find the value of x.

A. 40

B. 60

C. 75

D. 80

E. 90

Detailed Solution

Sum of ∠s in a pentagon = (n - 2)180 = 540°
x° + 2x° + x° + 60° + x° + 10° + x° - 10° = 540°
6x° + 60° = 540°; x = 80°
44.

In the diagram above, ∠PTQ = ∠URP = 25° and XPU = 4URP. Calculate ∠USQ.

A. 100o

B. 120o

C. 125o

D. 130o

E. 150o

Detailed Solution

Since < URP = 25°, then < XPU = 4 x 25° = 100°
\(\therefore\) < TPQ = 180° - 100° = 80°
\(\therefore\) < PQT = 180° - (80° + 25°) = 75°
< SQR = 75° - 25° = 50° (exterior angle = 2 opp interior angles)
\(\therefore\) < USQ = 180° - 50° = 130°

45.

In a given regular polygon, the ratio of the exterior angle to the interior angles is 1:3. How many side has the polygon?

A. 40

B. 5

C. 6

D. 8

E. 12

Detailed Solution

Let x be the exterior angle; interior = 3x; but x + 3x = 180o

4x = 180o; x = 45

= \(\frac{360}{45}\) = 8
46.

In the diagram above, O is the center of the circle, |SQ| = |QR| and ∠PQR = 68°. Calculate ∠PRS

A. 34o

B. 45o

C. 56o

D. 62o

E. 68o

Detailed Solution

From the figure, < PQR = 68°
\(\therefore\) < QRS = < QSR = \(\frac{180 - 68}{2}\) (base angles of an isos. triangle)
= 56°
\(\therefore\) < PRS = 90° - 56° = 34° (angles in a semi-circle)
47.

Find the area of an equivalent triangle of side 16cm

A. 64√3cm2

B. 72√3cm2

C. 96cm2

D. 128√3cm2

E. 128cm2

Detailed Solution

Area = 1/2 x 16 x 16sin60o = 64√3cm2
48.

In the diagram above, PQ and XY are two concentric arc; center O, the ratio of the length of the two arc is 1:3, find the ratio of the areas of the two sectors OPQ and OXY

A. 1:3

B. 1:6

C. 1:9

D. 2:3

E. 4:9

Detailed Solution

Let the radius of the arc PQ = r and the radius of the arc XY = R.
Length of arc PQ = \(\frac{\theta}{360} \times 2\pi r = 1\)
Length of arc XY = \(\frac{\theta}{360} \times 2\pi R = 3\)
Ratio of the arc = \(\frac{r}{R} = \frac{360 \times 2\pi \theta}{2\pi \theta \times 360 \times 3}\)
= \(\frac{1}{3}\)
Ratio of their area = \((\frac{1}{3})^2 = \frac{1}{9}\)
= 1 : 9
49.

In the diagram above , |AD| = 10cm, |DC| = 8cm and |CF| = 15cmIf the area of triangle DCF = 24cm2, find the area of the quadrilateral ABCD.

A. 24cm2

B. 48cm2

C. 80cm2

D. 96cm2

E. 120cm2

Detailed Solution

Area of \(\Delta\)DCF = 24cm2

Area of Quad= 2 x 24 = 48cm2
50.

In the diagram above , |AD| = 10cm, |DC| = 8cm and |CF| = 15cm. Which of the following is correct?

A. Area BCF = Area DCF

B. Area ADE = Area ADF

C. Area ADE = Area DCFE

D. Area CBF = Area DABC

E. Area DABO = Area CFEO

E

41.

Mrs. Jones is expecting a baby. The probability that it will be a boy is 1/2 and probability that the baby will have blue eyes is 1/4. What is the probability that she will have a blue-eyed boy?

A. 1/8

B. 1/4

C. 3/8

D. 1/2

E. 3/4

Detailed Solution

(1/2)(1/4) = 1/8
42.

Which of the following about a rhombus may not be true?

A. The diagonals are equal

B. The diagonals bisect the angles through which they pass

C. the diagonals bisect each other

D. The adjacent sides are equal

E. Opposite angles are equal

A

43.

The angles of a pentagon are x°, 2x°, (x + 60)°, (x + 10)°, (x -10)°. Find the value of x.

A. 40

B. 60

C. 75

D. 80

E. 90

Detailed Solution

Sum of ∠s in a pentagon = (n - 2)180 = 540°
x° + 2x° + x° + 60° + x° + 10° + x° - 10° = 540°
6x° + 60° = 540°; x = 80°
44.

In the diagram above, ∠PTQ = ∠URP = 25° and XPU = 4URP. Calculate ∠USQ.

A. 100o

B. 120o

C. 125o

D. 130o

E. 150o

Detailed Solution

Since < URP = 25°, then < XPU = 4 x 25° = 100°
\(\therefore\) < TPQ = 180° - 100° = 80°
\(\therefore\) < PQT = 180° - (80° + 25°) = 75°
< SQR = 75° - 25° = 50° (exterior angle = 2 opp interior angles)
\(\therefore\) < USQ = 180° - 50° = 130°

45.

In a given regular polygon, the ratio of the exterior angle to the interior angles is 1:3. How many side has the polygon?

A. 40

B. 5

C. 6

D. 8

E. 12

Detailed Solution

Let x be the exterior angle; interior = 3x; but x + 3x = 180o

4x = 180o; x = 45

= \(\frac{360}{45}\) = 8
46.

In the diagram above, O is the center of the circle, |SQ| = |QR| and ∠PQR = 68°. Calculate ∠PRS

A. 34o

B. 45o

C. 56o

D. 62o

E. 68o

Detailed Solution

From the figure, < PQR = 68°
\(\therefore\) < QRS = < QSR = \(\frac{180 - 68}{2}\) (base angles of an isos. triangle)
= 56°
\(\therefore\) < PRS = 90° - 56° = 34° (angles in a semi-circle)
47.

Find the area of an equivalent triangle of side 16cm

A. 64√3cm2

B. 72√3cm2

C. 96cm2

D. 128√3cm2

E. 128cm2

Detailed Solution

Area = 1/2 x 16 x 16sin60o = 64√3cm2
48.

In the diagram above, PQ and XY are two concentric arc; center O, the ratio of the length of the two arc is 1:3, find the ratio of the areas of the two sectors OPQ and OXY

A. 1:3

B. 1:6

C. 1:9

D. 2:3

E. 4:9

Detailed Solution

Let the radius of the arc PQ = r and the radius of the arc XY = R.
Length of arc PQ = \(\frac{\theta}{360} \times 2\pi r = 1\)
Length of arc XY = \(\frac{\theta}{360} \times 2\pi R = 3\)
Ratio of the arc = \(\frac{r}{R} = \frac{360 \times 2\pi \theta}{2\pi \theta \times 360 \times 3}\)
= \(\frac{1}{3}\)
Ratio of their area = \((\frac{1}{3})^2 = \frac{1}{9}\)
= 1 : 9
49.

In the diagram above , |AD| = 10cm, |DC| = 8cm and |CF| = 15cmIf the area of triangle DCF = 24cm2, find the area of the quadrilateral ABCD.

A. 24cm2

B. 48cm2

C. 80cm2

D. 96cm2

E. 120cm2

Detailed Solution

Area of \(\Delta\)DCF = 24cm2

Area of Quad= 2 x 24 = 48cm2
50.

In the diagram above , |AD| = 10cm, |DC| = 8cm and |CF| = 15cm. Which of the following is correct?

A. Area BCF = Area DCF

B. Area ADE = Area ADF

C. Area ADE = Area DCFE

D. Area CBF = Area DABC

E. Area DABO = Area CFEO

E