1998 - WAEC Mathematics Past Questions and Answers - page 2
11
Find the number whose logarithm to base 10 is 2.6025
A
0.0004
B
4.004
C
40.04
D
400.4
correct option: d
Users' Answers & Comments12
A piece of cloth was measured as 6.10m. If the actual length of the cloth is 6.35, find the percentage error, correct to 2 decimal places
A
3.05%
B
3.95%
C
15.00%
D
25.00%
correct option: b
Users' Answers & Comments13
Simplify \(\frac{8^{\frac{2}{3}}*27^{\frac{-1}{3}}}{64^{\frac{1}{3}}}\)
A
-3
B
\(\frac{1}{9}\)
C
\(\frac{1}{3}\)
D
\(\frac{27}{8}\)
correct option: c
\(\frac{8^{\frac{2}{3}}*27^{\frac{-1}{3}}}{64^{\frac{1}{3}}}\)
\(\frac{2^2*3^{-3}}{4} = 3^{-1} = \frac{1}{3}\)
Users' Answers & Comments\(\frac{2^2*3^{-3}}{4} = 3^{-1} = \frac{1}{3}\)
14
Solve the equation 5x2 - 4x - 1 = 0
A
-1, 1/5
B
-1, -1/5
C
1, 1/5
D
1, -1/5
correct option: d
5x2 - 4x - 1 = 0
5x2 5x + x -1 = 0
5x(x - 1) + (x - 1) = 0
(5x + 1)(x -1) = 0
x = -1/5 or 1 = 0
Users' Answers & Comments5x2 5x + x -1 = 0
5x(x - 1) + (x - 1) = 0
(5x + 1)(x -1) = 0
x = -1/5 or 1 = 0
15
p and q are two positive numbers such that p > 2q. Which one of the following statements is not true?
A
-p < -2q
B
-p > -2q
C
-q < 2p
D
q < 1/2p
correct option: b
Users' Answers & Comments16
For what value of x is the expression
x - 5/x2 - 2x - 3
A
3, 1
B
-1, -3
C
-1, 3
D
3, -2
correct option: c
Users' Answers & Comments17
Make S the subject of the formula: \(V = \frac{K}{\sqrt{T-S}}\)
A
\(T-\frac{K^2}{V^2} = S\)
B
\(T+\frac{K^2}{V^2} = S\)
C
\(T-\frac{K^2}{V} = S\)
D
\(T-\frac{K}{V} = S\)
correct option: a
\(V = \frac{K}{\sqrt{T-S}}\)
square both sides of the equation
\(V^2 = \frac{K^2}{T-S}\)
cross multiply
\(V^2 T - S = K^2\)
\(T - S = \frac{K^2}{V^2}\)
\(T = \frac{K^2}{V^2} + S\)
\(T - = \frac{K^2}{V^2} = S\)
Users' Answers & Commentssquare both sides of the equation
\(V^2 = \frac{K^2}{T-S}\)
cross multiply
\(V^2 T - S = K^2\)
\(T - S = \frac{K^2}{V^2}\)
\(T = \frac{K^2}{V^2} + S\)
\(T - = \frac{K^2}{V^2} = S\)
18
Find the equation whose roots are \(\frac{2}{3}and \frac{-1}{4}\)
A
\(12x^2+11x+2=0\)
B
\(12x^2-11x+2=0\)
C
\(x^2-\frac{11}{12}x+2=0\)
D
\(x^2+\frac{11}{12}x-2=0\)
correct option: a
Users' Answers & Comments20
solve the inequality \((Y-3)<\frac{y}{3}\)
A
y > -9
B
y < 3
C
y > 4
D
y < 9
correct option: c
\((Y-3)<\frac{y}{3}\
3y - 9 < y\
2y< 9\
y < 4\frac{1}{2}\)
Users' Answers & Comments3y - 9 < y\
2y< 9\
y < 4\frac{1}{2}\)