# 2003 - WAEC Mathematics Past Questions & Answers - page 1

1

Simplify $$\left(\frac{3}{4} - \frac{1}{3}\right)\times 4\frac{1}{3}\div 3\frac{1}{4}$$

A
$$\frac{5}{9}$$
B
$$\frac{5}{16}$$
C
$$\frac{8}{13}$$
D
$$\frac{16}{5}$$
CORRECT OPTION: a

$$(\frac{3}{4} - \frac{1}{3}) \times 4\frac{1}{3} \div 3\frac{1}{4}$$

= $$(\frac{9 - 4}{12}) \times \frac{13}{3} \div \frac{13}{4}$$

= $$\frac{5}{12} \times \frac{13}{3} \times \frac{4}{13}$$

= $$\frac{5}{9}$$

2

The table below gives the distribution of marks obtained by a number of pupils in a class test.

The mode of the distribution is

A
3
B
5
C
8
D
18
CORRECT OPTION: a
3

The table below gives the distribution of marks obtained by a number of pupils in a class test.

Find the median of the distribution

A
1
B
2
C
3
D
4
CORRECT OPTION: c
4

The table below gives the distribution of marks obtained by a number of pupils in a class test.

How many pupils scored at least 2 marks?

A
12
B
23
C
37
D
49
CORRECT OPTION: d

= 12 + 18 + 11 + 8

= 49 students

5
A student bought 3 notebooks and 1 pen for N35. After misplacing these items, she again bought 2 notebooks and 2 pens, all of the same type for
N30. What is the cost of a pen?
A
N5.00
B
N7.50
C
N10.00
D
N15.00
CORRECT OPTION: a
Represent notebook with x
Represent pen with y
∴ 3x+y=35 ---- (i)
2x+2y=30 ---- (ii)
Multiply eqn (i) by 2 and eqn (ii) by 1
6x+2y=70 ---- (iii)
2x+2y=30 ---- (iv)
Subtract eqn (iv) from eqn (iii)
4x = 40
X = 10
Substitute x = 10 in eqn (i)
3x+y=35
3(10)+y=35
Y = 5
∴ The cost of pen is N5.00
6
Simplify $$\frac{4}{a-3}-\frac{1}{a+3}$$
A
$$\frac{3a+11}{(a-3)(a-2)}$$
B
$$\frac{3a+11}{(a+3)(a-2)}$$
C
$$\frac{3a+11}{(a+3)(a+2)}$$
D
$$\frac{3a+11}{(a-3)(a+2)}$$
CORRECT OPTION: d
$$\frac{4}{a-3}-\frac{1}{a+3}\ = \frac{4(a+2)-1(a-3)}{(a-3)(a+2)}\ =\frac{3a+11}{(a-3)(a+2)}$$
7
Simplify $$\frac{4\sqrt{18}}{\sqrt{8}}$$
A
2
B
3
C
6
D
12
CORRECT OPTION: c
$$\frac{4\sqrt{18}}{\sqrt{8}}\ = \frac{4\sqrt{9\times 2}}{\sqrt{4 \times 2}} = \frac{12\sqrt{2}}{2\sqrt{2}}=\frac{6\sqrt{2}}{\sqrt{2}}\ Rationalising \frac{6\sqrt{2}}{\sqrt{2}}\ =\frac{6\sqrt{2}}{\sqrt{2}} \times \frac{\sqrt{2}}{\sqrt{2}} = 6$$
8
In the diagram, PQ/RT /RS/ =/QS/, ∠QST= 70o and ∠PQW = 55o
Find the size of reflex ∠WQS
A
235o
B
290o
C
305o
D
325o
CORRECT OPTION: a
Reflex ∠WQS = 360o - (55o + 70o)
=360o - 125o = 235o
9

Three men, Bedu, Bakre and Kofi shared' N500 in the ratio 3:2: x respectively. If Bedu’s share is N150, find the value of x.

A
1
B
4
C
5
D
6
CORRECT OPTION: c

$$5+x\rightarrow 500\ 3 \rightarrow 150\ ∴ 3 \times 500 = 150 \times (5+x)\ 1500 = 750 + 150x\ x=\frac{750}{150}=5$$

10

Simplify $$\left(1\frac{2}{3}\right)^2 - \left(\frac{2}{3}\right)^2$$

A
$$2\frac{1}{3}$$
B
$$1\frac{1}{3}$$
C
1
D
$$\frac{3}{7}$$
CORRECT OPTION: a

$$\left(1\frac{2}{3}\right)^2 - \left(\frac{2}{3}\right)^2=\left(\frac{5}{3}\right)^2 - \left(\frac{2}{3}\right)^2$$
Difference of two squares
$$\left(\frac{5}{3}-\frac{2}{3}\right)\left(\frac{5}{3}+\frac{2}{3}\right)=\left(\frac{3}{3}\right)\left(\frac{7}{3}\right)\ \frac{7}{3}=2\frac{1}{3}$$

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