Year : 
2010
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

41 - 49 of 49 Questions

# Question Ans
41.

In the diagram, < ROS = 66o and < POQ = 3x. some construction lines are shown. Calculate the value of x.

A. 10o

B. 11o

C. 22o

D. 35o

Detailed Solution

From the diagram, OP bisects < ROS

< POS = \(\frac{1}{2}\) < ROS = \(\frac{1}{2}\) x 66o

3x = 33o

x = \(\frac{33^o}{3}\)

= 11o
42.

In the diagram, the tangent MN makes an angle of 55o with the chord PS. IF O is the centre of the circle, find < RPS

A. 55o

B. 45o

C. 35o

D. 25o

Detailed Solution

Join SR

< PRS = 90o(Angle in a semicircle)

< PRS = 55o (Angle between a chord and a tangent = Angle in the alternate segment)

< PSR + < PRS + < RSP = 180o

90v + 55o + < RSp = 180o

< RSP = 180o - 145o

= 35o
43.

In the diagram, O is the centre of the circle, < SQR = 60o, < SPR = y and < SOR = 3x. Find the value of (x + y)

A. 110o

B. 100o

C. 80o

D. 70o

Detailed Solution

3x = 2 x 60 = 2y (Angle at centre = 2 x angle at circumference)

3x = 2 x 60

x = \(\frac{2 \times 60}{3}\) = 40o

2 x 60 = 2y

y = 60o

x + y = 40 + 60

= 100o
44.

The shaded portion in the diagram is the solution of

A. x + y \(\leq\) 3

B. x + y < 3

C. x + y > 3

D. x + y \(\geq\) 3

Detailed Solution

Using \(\frac{x}{a} + \frac{y}{b}\) < 1for the equation of the time

where a = intercept on x-axis and b = intercept on y - axis

\(\frac{x}{3} + \frac{y}{3} = 1\)

= \(\frac{x + y}{3} = 1\)

= x + y < 3
45.

In the diagram, GI is a tangent to the circle at H. If EF//GI, calculate the size of < EHF

A. 126o

B. 72o

C. 64cmo

D. 32cmo

Detailed Solution

F = 54o (Alternate triangle angles)

< GHE = F = 54o(Angle between a chord and a tangent = angles in the alternate segment)

Now, < GHE + < EHF + < IHF = 180o(Angles on a straight line)

54o + < EHF + 54o = 180o

< EHF = 180o - 108o

= 72o
46.

The diagram is a net right rectangular pyramid. Calculate the total surface area

A. 208cm2

B. 112cm2

C. 92cm2

D. 76cm2

Detailed Solution

Total surface area = sum of the area of the \(\bigtriangleup\) S + Area of the rectangle

= 2 x Area of \(\bigtriangleup\) PTQ + 2 x Area of \(\bigtriangleup\) QUR + Area of rectangle PQRS

2 x \(\frac{1}{2}\)(8 x 4) + 2 x \(\frac{1}{2}\)(5 x 4) + 8 x 5

= 32 + 20 + 40

= 92cm2
47.

The diagram shows a rectangular cardboard from which a semi-circle is cut off. Calculate the area of the remaining part

A. 44cm2

B. 99cm2

C. 154cm2

D. 165cm2

Detailed Solution

Area of remaining = Area of rectangle = Area of semi-circle

22 x 8 - \(\frac{1}{2}\)xar2

ehere r - \(\frac{14}{2}\)cm = 7cm

Area of remaining = 176 - \(\frac{1}{2}\) x \(\frac{22}{4}\) x 7 x 7

= 176 - 77

= 99cm2
48.

In the diagram, 0 is the centre of the circle. Find the value x

A. 34

B. 29

C. 17

D. 14

Detailed Solution

POQ in a straight line

Hence, < POQ + < QOR = 180o

56o + < QOR = 180o

< QOR = 180o - 56o

= 124o

Now, in \(\bigtriangleup\) QOR OR = OQ = Radius

< ORQ = < OQR = 2x (Base angles of an Isosceles \(\bigtriangleup\))

2x + 124 + 2x = 180o

4x + 124 = 180

4x = 180 - 124

4x = 56

x = \(\frac{56}{4}\)

x = 14o
49.

In the diagram, < WOX = 60o, < YOE = 50o and < OXY = 30o. What is the bearing of x from y?

A. 300o

B. 240o

C. 190o

D. 150o

Detailed Solution

The bearing of x from y = 270o + \(\theta\)

where \(\theta\) + 50o = y

in \(\bigtriangleup\) OXY

O + X + Y = 180o

Where O = 40o + 30o = 70o

70o + 30o + y = 180o

y + 100o = 180o

y = 180o - 100o = 30o

\(\theta\) + 50o = 80
41.

In the diagram, < ROS = 66o and < POQ = 3x. some construction lines are shown. Calculate the value of x.

A. 10o

B. 11o

C. 22o

D. 35o

Detailed Solution

From the diagram, OP bisects < ROS

< POS = \(\frac{1}{2}\) < ROS = \(\frac{1}{2}\) x 66o

3x = 33o

x = \(\frac{33^o}{3}\)

= 11o
42.

In the diagram, the tangent MN makes an angle of 55o with the chord PS. IF O is the centre of the circle, find < RPS

A. 55o

B. 45o

C. 35o

D. 25o

Detailed Solution

Join SR

< PRS = 90o(Angle in a semicircle)

< PRS = 55o (Angle between a chord and a tangent = Angle in the alternate segment)

< PSR + < PRS + < RSP = 180o

90v + 55o + < RSp = 180o

< RSP = 180o - 145o

= 35o
43.

In the diagram, O is the centre of the circle, < SQR = 60o, < SPR = y and < SOR = 3x. Find the value of (x + y)

A. 110o

B. 100o

C. 80o

D. 70o

Detailed Solution

3x = 2 x 60 = 2y (Angle at centre = 2 x angle at circumference)

3x = 2 x 60

x = \(\frac{2 \times 60}{3}\) = 40o

2 x 60 = 2y

y = 60o

x + y = 40 + 60

= 100o
44.

The shaded portion in the diagram is the solution of

A. x + y \(\leq\) 3

B. x + y < 3

C. x + y > 3

D. x + y \(\geq\) 3

Detailed Solution

Using \(\frac{x}{a} + \frac{y}{b}\) < 1for the equation of the time

where a = intercept on x-axis and b = intercept on y - axis

\(\frac{x}{3} + \frac{y}{3} = 1\)

= \(\frac{x + y}{3} = 1\)

= x + y < 3
45.

In the diagram, GI is a tangent to the circle at H. If EF//GI, calculate the size of < EHF

A. 126o

B. 72o

C. 64cmo

D. 32cmo

Detailed Solution

F = 54o (Alternate triangle angles)

< GHE = F = 54o(Angle between a chord and a tangent = angles in the alternate segment)

Now, < GHE + < EHF + < IHF = 180o(Angles on a straight line)

54o + < EHF + 54o = 180o

< EHF = 180o - 108o

= 72o
46.

The diagram is a net right rectangular pyramid. Calculate the total surface area

A. 208cm2

B. 112cm2

C. 92cm2

D. 76cm2

Detailed Solution

Total surface area = sum of the area of the \(\bigtriangleup\) S + Area of the rectangle

= 2 x Area of \(\bigtriangleup\) PTQ + 2 x Area of \(\bigtriangleup\) QUR + Area of rectangle PQRS

2 x \(\frac{1}{2}\)(8 x 4) + 2 x \(\frac{1}{2}\)(5 x 4) + 8 x 5

= 32 + 20 + 40

= 92cm2
47.

The diagram shows a rectangular cardboard from which a semi-circle is cut off. Calculate the area of the remaining part

A. 44cm2

B. 99cm2

C. 154cm2

D. 165cm2

Detailed Solution

Area of remaining = Area of rectangle = Area of semi-circle

22 x 8 - \(\frac{1}{2}\)xar2

ehere r - \(\frac{14}{2}\)cm = 7cm

Area of remaining = 176 - \(\frac{1}{2}\) x \(\frac{22}{4}\) x 7 x 7

= 176 - 77

= 99cm2
48.

In the diagram, 0 is the centre of the circle. Find the value x

A. 34

B. 29

C. 17

D. 14

Detailed Solution

POQ in a straight line

Hence, < POQ + < QOR = 180o

56o + < QOR = 180o

< QOR = 180o - 56o

= 124o

Now, in \(\bigtriangleup\) QOR OR = OQ = Radius

< ORQ = < OQR = 2x (Base angles of an Isosceles \(\bigtriangleup\))

2x + 124 + 2x = 180o

4x + 124 = 180

4x = 180 - 124

4x = 56

x = \(\frac{56}{4}\)

x = 14o
49.

In the diagram, < WOX = 60o, < YOE = 50o and < OXY = 30o. What is the bearing of x from y?

A. 300o

B. 240o

C. 190o

D. 150o

Detailed Solution

The bearing of x from y = 270o + \(\theta\)

where \(\theta\) + 50o = y

in \(\bigtriangleup\) OXY

O + X + Y = 180o

Where O = 40o + 30o = 70o

70o + 30o + y = 180o

y + 100o = 180o

y = 180o - 100o = 30o

\(\theta\) + 50o = 80