WAEC Mathematics Past Questions & Answers - Page 106

526.

The graph is that of y = 2x² - 5x - 3. For what value of x will y be negative? What is the gradient of y = 2x² - 5x - 3 at the point x = 4?

11.1

10.5

10.3

9.9

View answer & explanation

Correct answer is A

No explanation has been provided for this answer.

527.

The bar chart shows the frequency distribution of marks scored by students in a class test. What is the median of the distribution?

View answer & explanation

Correct answer is A

median = (\(\frac{N + 1}{2}\))th = (\(\frac{25 + 1}{2}\))th

= \(\frac{26th}{2}\)

= 13th

the 13th is 2

528.

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

529.

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

530.

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