Year : 
2021
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

31 - 40 of 49 Questions

# Question Ans
31.

Find, correct to two decimal, the mean of 1\(\frac{1}{2}\), 2\(\frac{2}{3}\), 3\(\frac{3}{4}\), 4\(\frac{4}{5}\), and 5\(\frac{5}{6}\).

A. 3.71

B. 3.70

C. 3.69

D. 3.72

Detailed Solution

The mean = sum of 1\(\frac{1}{2}\), 2\(\frac{2}{3}\), 3\(\frac{3}{4}\), 4\(\frac{4}{5}\), and 5\(\frac{5}{6}\) divided by their quantity.
Mean = ( 1\(\frac{1}{2}\) + 2\(\frac{2}{3}\) + 3\(\frac{3}{4}\) + 4\(\frac{4}{5}\) + and 5\(\frac{5}{6}\) ) / 5
= 3.708 or 3.71( 2 d.p )
32.

A cyclist moved at a speed of Xkm/h for 2 hours. He then increased his speed by 2 km/h for the next 3 hours.If the total distance covered is 36 km, calculate his initials speed.

A. 12km/h

B. 3km/h

C. 4km/h

D. 6km/h

33.

Find the value of (x+y)

A. 215°

B. 70°

C. 135°

D. 145°

Detailed Solution

sum of angle in a straight line = 180°
35 + m = 180
m = 180 - 35 = 145°
Corresponding angles are congruent i.e equal to each other
Angle X and M are congruent = 145
sum of angle in a straight line = 180°
110 + n = 180
m = 180 - 110 = 70°
Angle Y and N are congruent = 70°
\(\therefore\) ( x + y) = ( 145 + 70)°
(x + y) = 215°

34.

In the diagram, \(\overline{MP}\) is a tangent to the circle NQR, ∠NQR, ∠PNQ = 64 and | \(\overline{RQ}\) | = | \(\overline{RN}\) |. Find the angle market t.

A. 130°

B. 115°

C. 58°

D. 68°

Detailed Solution

Alternate segments are equal : R° = 64°
An isosceles triangle has two angles ( Q° & N° ) equal as A°
R° + A° + A° = 180°
2A°= 180 - 64
2A° = 116°
A = \(\frac{116}{2}\)
A = 58.
: Q° = 58, N° = 58 and T° = 58
As Alternate segments are equal: T = Q

35.

Find the first quartile of 7,8,7,9,11,8,7,9,6 and 8.

A. 8.5

B. 7.0

C. 7.5

D. 8.0

Detailed Solution

Rearrange data in increasing order: 6,7,7,7,8,8,8,9,9 and 11
First quartile (ungrouped data) = \(\frac{n}{4}\)th value
= \(\frac{10}{4}\)
= 2.5th value
= \(\frac{7 + 7}{2}\)
= 7.0
36.

In the diagram, PQRS is a circle. find the value of x.

A. 50°

B. 30°

C. 80°

D. 100°

Detailed Solution

Opp. angles in a cyclic quadrilateral always add up to 180°
∠P + ∠R & ∠Q + ∠S = 180
x + x+y = 180
2x + y = 180... i
2y - 30 + x = 180
2y + x = 180 + 30
x + 2y = 210 ... ii
Elimination method:
(2x + y = 180) * 1 --> 2x + y = 180
(x + 2y = 210) * 2 --> 2x + 4y = 420
Subtracting both equations
- 3y = - 240
y = 80°
using eqn i
2x + y = 180
2x + 80 = 180
2x = 100
x = 50°
37.

A cone has a base radius of 8cm and height 11cm. calculate , correct to 2d.p, the curved surface area

A. 341.98cm\(^2\)

B. 276.57cm\(^2\)

C. 201.14cm\(^2\)

D. 477.71cm\(^2\)

Detailed Solution

Where l\(^2\) = h\(^2\) + r\(^2\)
l\(^2\) = 11\(^2\) + 8\(^2\)
l = √185
l = 13.60cm
The formula of CSA of Cone is πrl
\(\frac{22}{7}\) * 8 * 13.60
= 341.979 or 341.98 (2d.p)
38.

Given that sin x = 3/5, 0 ≤ x ≤ 90, evaluate (tanx + 2cosx)

A. 2\(\frac{11}{20}\)

B. \(\frac{11}{20}\)

C. 2\(\frac{7}{20}\)

D. \(\frac{1}{20}\)

Detailed Solution

Sin x = \(\frac{opp}{hyp}\)
sinx = \(\frac{3}{5}\)
using Pythagoras' theorem
hyp\(^2\) = opp\(^2\) + adj\(^2\)
adj\(^2\) = 5\(^2\) - 3\(^2\) = 25 - 9
adj\(^2\) = 16
adj = 16
adj = 4.
tanx = \(\frac{opp}{adj}\)
= \(\frac{3}{4}\)
cosx = \(\frac{adj}{hyp}\)
= \(\frac{4}{5}\)
(tanx + 2cosx) = \(\frac{3}{4}\) + 2(\(\frac{4}{5}\))
= \(\frac{15 + 32}{20}\)
= \(\frac{47}{20}\) or
2 \(\frac{7}{20}\)
39.

In the diagram, line \(\overline{EC}\) is a diameter of the circle ABCDE.If angle ABC equals 158°, find ∠ADE

A. 112

B. 90

C. 68

D. 22

C

40.

Table:
The table shows the height of 37 players of a basketball team calculates correct to one decimal place the mean height of the players.

A. 163.0

B. 162.0

C. 160.0

D. 165.0

Detailed Solution

∑fx = (160 * 4) + (161 * 6) + (162 * 3) + (163 * 7) + (164 * 8) + (165 * 9)
=640 + 966 + 486 + 1,141 + 1,312 + 1,485
= 6,030
∑f = 4 + 6 + 3 + 7 + 8 + 9
= 37
= \(\frac{∑fx}{∑f}\)
= \(\frac{6030}{37}\)
= 162.97 or 163
31.

Find, correct to two decimal, the mean of 1\(\frac{1}{2}\), 2\(\frac{2}{3}\), 3\(\frac{3}{4}\), 4\(\frac{4}{5}\), and 5\(\frac{5}{6}\).

A. 3.71

B. 3.70

C. 3.69

D. 3.72

Detailed Solution

The mean = sum of 1\(\frac{1}{2}\), 2\(\frac{2}{3}\), 3\(\frac{3}{4}\), 4\(\frac{4}{5}\), and 5\(\frac{5}{6}\) divided by their quantity.
Mean = ( 1\(\frac{1}{2}\) + 2\(\frac{2}{3}\) + 3\(\frac{3}{4}\) + 4\(\frac{4}{5}\) + and 5\(\frac{5}{6}\) ) / 5
= 3.708 or 3.71( 2 d.p )
32.

A cyclist moved at a speed of Xkm/h for 2 hours. He then increased his speed by 2 km/h for the next 3 hours.If the total distance covered is 36 km, calculate his initials speed.

A. 12km/h

B. 3km/h

C. 4km/h

D. 6km/h

33.

Find the value of (x+y)

A. 215°

B. 70°

C. 135°

D. 145°

Detailed Solution

sum of angle in a straight line = 180°
35 + m = 180
m = 180 - 35 = 145°
Corresponding angles are congruent i.e equal to each other
Angle X and M are congruent = 145
sum of angle in a straight line = 180°
110 + n = 180
m = 180 - 110 = 70°
Angle Y and N are congruent = 70°
\(\therefore\) ( x + y) = ( 145 + 70)°
(x + y) = 215°

34.

In the diagram, \(\overline{MP}\) is a tangent to the circle NQR, ∠NQR, ∠PNQ = 64 and | \(\overline{RQ}\) | = | \(\overline{RN}\) |. Find the angle market t.

A. 130°

B. 115°

C. 58°

D. 68°

Detailed Solution

Alternate segments are equal : R° = 64°
An isosceles triangle has two angles ( Q° & N° ) equal as A°
R° + A° + A° = 180°
2A°= 180 - 64
2A° = 116°
A = \(\frac{116}{2}\)
A = 58.
: Q° = 58, N° = 58 and T° = 58
As Alternate segments are equal: T = Q

35.

Find the first quartile of 7,8,7,9,11,8,7,9,6 and 8.

A. 8.5

B. 7.0

C. 7.5

D. 8.0

Detailed Solution

Rearrange data in increasing order: 6,7,7,7,8,8,8,9,9 and 11
First quartile (ungrouped data) = \(\frac{n}{4}\)th value
= \(\frac{10}{4}\)
= 2.5th value
= \(\frac{7 + 7}{2}\)
= 7.0
36.

In the diagram, PQRS is a circle. find the value of x.

A. 50°

B. 30°

C. 80°

D. 100°

Detailed Solution

Opp. angles in a cyclic quadrilateral always add up to 180°
∠P + ∠R & ∠Q + ∠S = 180
x + x+y = 180
2x + y = 180... i
2y - 30 + x = 180
2y + x = 180 + 30
x + 2y = 210 ... ii
Elimination method:
(2x + y = 180) * 1 --> 2x + y = 180
(x + 2y = 210) * 2 --> 2x + 4y = 420
Subtracting both equations
- 3y = - 240
y = 80°
using eqn i
2x + y = 180
2x + 80 = 180
2x = 100
x = 50°
37.

A cone has a base radius of 8cm and height 11cm. calculate , correct to 2d.p, the curved surface area

A. 341.98cm\(^2\)

B. 276.57cm\(^2\)

C. 201.14cm\(^2\)

D. 477.71cm\(^2\)

Detailed Solution

Where l\(^2\) = h\(^2\) + r\(^2\)
l\(^2\) = 11\(^2\) + 8\(^2\)
l = √185
l = 13.60cm
The formula of CSA of Cone is πrl
\(\frac{22}{7}\) * 8 * 13.60
= 341.979 or 341.98 (2d.p)
38.

Given that sin x = 3/5, 0 ≤ x ≤ 90, evaluate (tanx + 2cosx)

A. 2\(\frac{11}{20}\)

B. \(\frac{11}{20}\)

C. 2\(\frac{7}{20}\)

D. \(\frac{1}{20}\)

Detailed Solution

Sin x = \(\frac{opp}{hyp}\)
sinx = \(\frac{3}{5}\)
using Pythagoras' theorem
hyp\(^2\) = opp\(^2\) + adj\(^2\)
adj\(^2\) = 5\(^2\) - 3\(^2\) = 25 - 9
adj\(^2\) = 16
adj = 16
adj = 4.
tanx = \(\frac{opp}{adj}\)
= \(\frac{3}{4}\)
cosx = \(\frac{adj}{hyp}\)
= \(\frac{4}{5}\)
(tanx + 2cosx) = \(\frac{3}{4}\) + 2(\(\frac{4}{5}\))
= \(\frac{15 + 32}{20}\)
= \(\frac{47}{20}\) or
2 \(\frac{7}{20}\)
39.

In the diagram, line \(\overline{EC}\) is a diameter of the circle ABCDE.If angle ABC equals 158°, find ∠ADE

A. 112

B. 90

C. 68

D. 22

C

40.

Table:
The table shows the height of 37 players of a basketball team calculates correct to one decimal place the mean height of the players.

A. 163.0

B. 162.0

C. 160.0

D. 165.0

Detailed Solution

∑fx = (160 * 4) + (161 * 6) + (162 * 3) + (163 * 7) + (164 * 8) + (165 * 9)
=640 + 966 + 486 + 1,141 + 1,312 + 1,485
= 6,030
∑f = 4 + 6 + 3 + 7 + 8 + 9
= 37
= \(\frac{∑fx}{∑f}\)
= \(\frac{6030}{37}\)
= 162.97 or 163