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WAEC Mathematics Past Questions & Answers - Page 106

526.

The bar chart shows the frequency distribution of marks scored by students in a class test. Calculate the mean of the distribution.

6.0

3.0

2.4

1.8

View answer & explanation

Correct answer is C

$\begin{array}{c|c} x & f & fx\\ \hline 1 & 6 & 6 \\ 2 & 8 & 16\\ 3 & 8 & 18\\ 4 & 5 & 20\end{array}$

mean x = $\frac{\sum fx}{\sum f}$

= $\frac{60}{25}$

x = 2.4

527.

The bar chart shows the frequency distribution of marks scored by students in a class test. How many students are in the class?

View answer & explanation

Correct answer is C

6 + 8 + 6 + 5 = 25

528.

The position of three ships P,Q and R at sea are illustrated in the diagram. The arrows indicated the North direction. The bearing of Q from P is 050o and < PQR = 72o. Calculate the bearing of R and Q

155^o

80^o

158^o

91^o

View answer & explanation

Correct answer is C

< NPQ = < PQB = 50^o(alt. < s)

< PQB = 50^o

< PQR = < PQR < PQB + < QBR = 72^o

< QBR = < PQR - < PQB = 72^o - 50^o

= 22^o

< NQR = 180 - < QBR = 180^o - 22 = 158^o, the bearing of R from Q = 158^o

529.

Is the diagram, MN, PQ and RS are three intersecting straight lines. Which of the following statements is/are true? i. t = y ii. x + y + z + m = 180o iii. x + m + n = 180o iv. x + n = m + z

i and iv

iii

View answer & explanation

Correct answer is C

m + y + x = 180o(sum of < s on straight line)

y = n(vertically opp. angle)

m + n + x = 180o

530.

In the diagram, MQ//RS, < TUV = 70^o and < RLV = 30^o. Find the value of x

150^o

110^o

100^o

95^o

View answer & explanation

Correct answer is C

L + 30^o - 180^o(Sum of < s on straight line)

L = 180^o - 30^o = 150^o

L = q = 150^o(opposite < s are equal)

y = b = 30^o(alt. < s)

b + c = 180^o(sum of < s on str. line)

30^o + c 180

c = 180 - 30

c = 150^o

b = a = 30^o (opp < s are equal)

c = d = 150^o (opp < s are equal)

a + k + 70^o = 180^o (sum of < s on $\bigtriangleup$ )

30^o + k + 70^o = 180

k + 100^o = 180

k = 180 - 100

k = 80^o

x + 80^o = 180(sum of < s on straight line)

x = 180^o - 80^o

x = 100^o