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

Paper 1 | Objectives

11 - 20 of 49 Questions

# Question Ans
11.

The circumference of a circular track is 9km. A cyclist rides round it a number of times and stops after covering a distance of 302km. How far is the cyclist from the starting point?

A. 5km

B. 6km

C. 7km

D. 3km

Detailed Solution

Circumference of the circular track = 9km
Distance covered = 302km
Number of complete circles or revolutions from the starting point = 302/9 =33 circles and additional 5km.
So, the distance of the cyclist from the starting point would be 5km
12.

Simplify 2√7- 14/√7+7/21

A. \(\frac{√21}{21}\)

B. 7\(\frac{√21}{21}\)

C. \(\frac{√21}{7}\)

D. 3√21

Detailed Solution

2√7- 14/√7 +7/√21
L.C.M is √21
\(\frac{√21 * 2√7 - √3 *14 + 7}{√21}\)
=\(\frac{2 * 7√3 - 14√3 + 7}{√21}\)
= \(\frac{14√3 - 14√3 + 7}{√21}\)
=\(\frac{7}{√21}\)
or
\(\frac{7 \times √21}{√21 \times √21}\)
= \(\frac{7 \times √21}{21}\) or \(\frac{√21}{3}\)
13.

If 4x+2y=16 and 6x-2y=4 , find the value of (y-x).

A. 8

B. 2

C. 4

D. 6

Detailed Solution

Using elimination method:
4x+2y=16 * 6 --> 24x +12y=96 ... eqn iii
6x-2y=4 * 4 --> 24x - 8y = 16 ... eqn iv
Subtract eqn iv from iii
20y = 80
y = 4
Subst. y for 4 in 4x + 2y = 16
--> 4x + 2(4) = 16
--> 4x = 16 - 8
--> 4x = 8
--> x = 2
: The value of (y-x) is 4 - 2 = 2

14.

In the diagram, ∠ABC and ∠BCD are right angles, ∠BAD = t and ∠EDF = 70°. Find the value of t.

A. 70°

B. 165°

C. 140°

D. 110°

Detailed Solution

Vertically opp angles are equal ∠CDE = 70°
Sum of interior angles in a quadilateral = 360°
(90 + 90 + 70 + t)° = 360°
t° = 360° - 250°
t° = 110°
15.

The sum of the interior angles of a regular polygon with k sides is (3k-10) right angles. Find the size of the exterior angle?

A. 60°

B. 40°

C. 90°

D. 120°

Detailed Solution

In a polygon with n sides, the sum of the angles =
(n - 2)180, where n = the number of sides.
In our problem, n = k.
So, we have:
(3k - 10)90 = (k - 2)180
270k - 900 = 180k - 360
Simplifying:
90k = 540
k = 6. So, we have a regular hexagon.
Now, each exterior angle = 360/n
We have: 360/6 = 60
Conclusion: Each exterior angle is 60 degrees.
16.

Make u the subject in x =\(\frac{2u-3}{3u + 2}\)

A. u = \(\frac{2x + 3}{3x - 2}\)

B. u = \(\frac{2x - 3}{3x - 2}\)

C. u = \(\frac{2x + 3}{2 - 3x}\)

D. u = \(\frac{2x + 3}{3x + 2}\)

Detailed Solution

x =\(\frac{2u-3}{3u + 2}\)
cross multiply
x(3u + 2) = 2u - 3
3ux + 2x = 2u - 3
collect like terms of u
2x + 3 = 2u - 3ux
\(\frac{2x + 3}{2 - 3x}\) = u
17.

A trader paid import duty of 38 kobo in the naira on the cost of an engine. If a total of #22,800.00 was paid as import duty, calculate the cost of the engine.

A. #60,000.00

B. #120,000.00

C. #24,000.00

D. #18,000.00

A

18.

The height of an equilateral triangle of side is 10 3√ cm. calculate its perimeter.

A. 20cm

B. 60cm

C. 40cm

D. 30cm

Detailed Solution

Height of an equilateral triangle, h = a\(\frac{√3}{2}\), where a is the side of the equilateral triangle.
10√3 = a\(\frac{√3}{2}\)
cross multiply--> 2 * 10√3 = a√3
√3 strikes √3 on both sides
20 = a
The perimeter of an equilateral triangle is: P = 3a
P = 3 * 20 = 60cm
P = 30√3
19.

In △LMN, |LM| = 6cm, ∠LNM = x and sin x = sin x = \(\frac{3}{5}\).Find the area of △LMN

A. 60cm\(^2\)

B. 48cm\(^2\)

C. 24cm\(^2\)

D. 30cm\(^2\)

C

20.

Consider the statements:P = All students offering Literature(L) also offer History(H);Q = Students offering History(H) do not offer Geography(G).Which of the Venn diagram correctly illustrate the two statements?

A. A

B. B

C. C

D. D

C

11.

The circumference of a circular track is 9km. A cyclist rides round it a number of times and stops after covering a distance of 302km. How far is the cyclist from the starting point?

A. 5km

B. 6km

C. 7km

D. 3km

Detailed Solution

Circumference of the circular track = 9km
Distance covered = 302km
Number of complete circles or revolutions from the starting point = 302/9 =33 circles and additional 5km.
So, the distance of the cyclist from the starting point would be 5km
12.

Simplify 2√7- 14/√7+7/21

A. \(\frac{√21}{21}\)

B. 7\(\frac{√21}{21}\)

C. \(\frac{√21}{7}\)

D. 3√21

Detailed Solution

2√7- 14/√7 +7/√21
L.C.M is √21
\(\frac{√21 * 2√7 - √3 *14 + 7}{√21}\)
=\(\frac{2 * 7√3 - 14√3 + 7}{√21}\)
= \(\frac{14√3 - 14√3 + 7}{√21}\)
=\(\frac{7}{√21}\)
or
\(\frac{7 \times √21}{√21 \times √21}\)
= \(\frac{7 \times √21}{21}\) or \(\frac{√21}{3}\)
13.

If 4x+2y=16 and 6x-2y=4 , find the value of (y-x).

A. 8

B. 2

C. 4

D. 6

Detailed Solution

Using elimination method:
4x+2y=16 * 6 --> 24x +12y=96 ... eqn iii
6x-2y=4 * 4 --> 24x - 8y = 16 ... eqn iv
Subtract eqn iv from iii
20y = 80
y = 4
Subst. y for 4 in 4x + 2y = 16
--> 4x + 2(4) = 16
--> 4x = 16 - 8
--> 4x = 8
--> x = 2
: The value of (y-x) is 4 - 2 = 2

14.

In the diagram, ∠ABC and ∠BCD are right angles, ∠BAD = t and ∠EDF = 70°. Find the value of t.

A. 70°

B. 165°

C. 140°

D. 110°

Detailed Solution

Vertically opp angles are equal ∠CDE = 70°
Sum of interior angles in a quadilateral = 360°
(90 + 90 + 70 + t)° = 360°
t° = 360° - 250°
t° = 110°
15.

The sum of the interior angles of a regular polygon with k sides is (3k-10) right angles. Find the size of the exterior angle?

A. 60°

B. 40°

C. 90°

D. 120°

Detailed Solution

In a polygon with n sides, the sum of the angles =
(n - 2)180, where n = the number of sides.
In our problem, n = k.
So, we have:
(3k - 10)90 = (k - 2)180
270k - 900 = 180k - 360
Simplifying:
90k = 540
k = 6. So, we have a regular hexagon.
Now, each exterior angle = 360/n
We have: 360/6 = 60
Conclusion: Each exterior angle is 60 degrees.
16.

Make u the subject in x =\(\frac{2u-3}{3u + 2}\)

A. u = \(\frac{2x + 3}{3x - 2}\)

B. u = \(\frac{2x - 3}{3x - 2}\)

C. u = \(\frac{2x + 3}{2 - 3x}\)

D. u = \(\frac{2x + 3}{3x + 2}\)

Detailed Solution

x =\(\frac{2u-3}{3u + 2}\)
cross multiply
x(3u + 2) = 2u - 3
3ux + 2x = 2u - 3
collect like terms of u
2x + 3 = 2u - 3ux
\(\frac{2x + 3}{2 - 3x}\) = u
17.

A trader paid import duty of 38 kobo in the naira on the cost of an engine. If a total of #22,800.00 was paid as import duty, calculate the cost of the engine.

A. #60,000.00

B. #120,000.00

C. #24,000.00

D. #18,000.00

A

18.

The height of an equilateral triangle of side is 10 3√ cm. calculate its perimeter.

A. 20cm

B. 60cm

C. 40cm

D. 30cm

Detailed Solution

Height of an equilateral triangle, h = a\(\frac{√3}{2}\), where a is the side of the equilateral triangle.
10√3 = a\(\frac{√3}{2}\)
cross multiply--> 2 * 10√3 = a√3
√3 strikes √3 on both sides
20 = a
The perimeter of an equilateral triangle is: P = 3a
P = 3 * 20 = 60cm
P = 30√3
19.

In △LMN, |LM| = 6cm, ∠LNM = x and sin x = sin x = \(\frac{3}{5}\).Find the area of △LMN

A. 60cm\(^2\)

B. 48cm\(^2\)

C. 24cm\(^2\)

D. 30cm\(^2\)

C

20.

Consider the statements:P = All students offering Literature(L) also offer History(H);Q = Students offering History(H) do not offer Geography(G).Which of the Venn diagram correctly illustrate the two statements?

A. A

B. B

C. C

D. D

C