# 2013 - WAEC Mathematics Past Questions and Answers - page 5

41
Using the histogram, estimate the mode of distribution
A
51.5
B
52.5
C
53.5
D
54.5
correct option: c
42
Using the histogram, what is the median class?
A
60.5 - 70.5
B
50.5 - 60.5
C
40.5 - 50.5
D
30.5 - 40.5
correct option: c
43
The pie chart shows the distribution of 600 mathematics textbooks for Arts, Business, Science and Technical Classes. How many textbooks are for the technical class?
A
100
B
150
C
200
D
250
correct option: d
Arts = 90o business = 75o, science = 45o

Technical 360o - (90o - 75o + 45o) = 360o - 210o

Technical = 150o

textbooks for technical class = $$\frac{150^o}{360^o}$$ x 600

= 250
44
The pie chart shows the distribution of 600 mathematics textbooks for Arts, Business, Science and Technical Classes. What percentage of the total number of textbooks belongs to science?
A
12$$\frac{1}{2}$$%
B
$$\frac{205}{6}$$%
C
25%
D
$$\frac{412}{3}$$%
correct option: a
$$\frac{45^o}{360}$$ x 100%

= 12$$\frac{1}{2}$$%
45
In the diagram, PQRST is a regular polygon with sides QR and TS produced to meet at V. Find the size of < RVS
A
36o
B
54o
C
60o
D
72o
correct option: a
PQRST is a regular polygon with 5 sides-pentagon n = 5, Each exterior angle = $$\frac{360^o}{n}$$

= $$\frac{350}{5}$$ = 70o

Each interior angle = 180 - 72o

(< s on str. line) = 180o

Since the pentagon is regular, the exterior angles are equal < R = 72o and < S = 72o

< RVS = 180o - (< R + < S)

= 180o - (72o + 72o)

= 180o - 144o

= 36o
46
In the diagram, PQ is a straight line. Calculate the value of the angle labelled 2y
A
130o
B
120o
C
110o
D
100o
correct option: d
Sum of angles on straight line = 180o

80o + 50o + x + 10o = 180o

140o + x = 180o

x = 180o - 140o

x = 40o

total sum of all angles = 360o

2yo + 2xo + 80o + 50o + x + 10o = 360o

2yo + 2(40)o + 80o + 50o + 40 + 10 = 360o

2yo + 80 + 180o = 360o

2yo + 260o = 360o

2yo = 360o - 260o

2yo = 100o

angle 2yo = 100o
47
In the diagram, ST//PQ reflex angle SRQ = 198o and < RQp = 72o. Find the value of y
A
18o
B
54o
C
87o
D
92o
correct option: b
R +198 = 360(angles at a point)

R = 360 - 198 = 162o

C = 72(alternate angle), b + c = 180(angles or straight line)

b = 190 - c = 180 - 72 = 108

a + b = R = 162

a = R - b = 162 - 108

= 54, but a = y(alternate angles)

y = 54o
48
Using the venn diagram, find n(x $$\cap$$ y1)
A
2
B
3
C
4
D
6
correct option: a
(x $$\cap$$ y2) = [a, b]

n(x $$\cap$$ y2) = 2