2006 - WAEC Mathematics Past Questions and Answers - page 1
1
Evaluate (0.13)\(^3\)correct to three significant figures
A
0.00219
B
0.00220
C
0.00300
D
0.00390
correct option: b
(0.13)\(^3\) = 0.13 x 0.13 x 0.13 = 0.002197
= 0.00220 (3 s.f)
Users' Answers & Comments= 0.00220 (3 s.f)
2
Simplify: 11011\(_2\) - 1101\(_2\)
A
101000\(_2\)
B
1100\(_2\)
C
1110\(_2\)
D
1011\(_2\)
3
Simplify \(\frac{25 \frac{2}{3} \div 25 \frac{1}{6}}{( \frac{1}{5})^{-\frac{7}{6}} \times ( \frac{1}{5})^{\frac{1}{6}}}\)
A
25
B
\(\frac{1}{5}\)
C
1
D
\(\frac{1}{25}\)
correct option: c
\(\frac{25 \frac{2}{3} \div 25 \frac{1}{6}}{( \frac{1}{5})^{-\frac{7}{6}} \times ( \frac{1}{5})^{\frac{1}{6}}}\) = \(\frac{25^{4 - \frac{1}{6}}}{(\frac{1}{5})^{-7 + \frac{1}{6}}}\)
= \(\frac{25^{\frac{1}{2}}}{(\frac{1}{5})^{-1}}\)
= \(\frac{(5^2)^{\frac{1}{2}}}{(5^{-1})^{-1}}\)
= \(\frac{5}{5}\)
= 1
Users' Answers & Comments= \(\frac{25^{\frac{1}{2}}}{(\frac{1}{5})^{-1}}\)
= \(\frac{(5^2)^{\frac{1}{2}}}{(5^{-1})^{-1}}\)
= \(\frac{5}{5}\)
= 1
4
Simplify \(\frac{x - 4}{4} - \frac{x - 3}{6}\)
A
\(\frac{x - 18}{12}\)
B
\(\frac{x - 6}{12}\)
C
\(\frac{x - 18}{24}\)
D
\(\frac{x - 6}{24}\)
correct option: b
\(\frac{x - 4}{4} - \frac{x - 3}{6}\) = \(\frac{3(x - 4) - 2(x - 3)}{12}\)
= \(\frac{3x -12 - 2x + 6}{12}\)
= \(\frac{3x - 2x - 12 + 6}{12}\)
= \(\frac{x - 6}{12}\)
Users' Answers & Comments= \(\frac{3x -12 - 2x + 6}{12}\)
= \(\frac{3x - 2x - 12 + 6}{12}\)
= \(\frac{x - 6}{12}\)
5
Given that y = 1 - \(\frac{2x}{4x - 3}\), find the value of x for which y is undefined
A
3
B
\(\frac{3}{4}\)
C
\(\frac{-3}{4}\)
D
-3
correct option: b
for undefined expression, the denomination is zero 4x - 3 = 0
4x = 3; x = \(\frac{3}{4}\)
Users' Answers & Comments4x = 3; x = \(\frac{3}{4}\)
6
P is a point on the same plane with a fixed point A. If P moves such that it is always equidistant from A, the locus of P is
A
a straight line joining A and P
B
the perpendicular bisector of AP
C
a circle with centre A
D
the triangle with centre P
correct option: c
Users' Answers & Comments7
A fair coin is tossed three times. Find the probability of getting two heads and one tail.
A
\(\frac{1}{2}\)
B
\(\frac{3}{8}\)
C
\(\frac{1}{4}\)
D
\(\frac{1}{8}\)
correct option: b
Pr(head) = \(\frac{1}{2}\), Pr(tail) = \(\frac{1}{2}\):Pr(2 heads)
= \(\frac{1}{2}\) x \(\frac{1}{2}\) = \(\frac{1}{4}\)
Pr(2 heads and tail) 3 times
= (\(\frac{1}{4}\) x \(\frac{1}{2}\)) x 3
= \(\frac{3}{8}\)
Users' Answers & Comments= \(\frac{1}{2}\) x \(\frac{1}{2}\) = \(\frac{1}{4}\)
Pr(2 heads and tail) 3 times
= (\(\frac{1}{4}\) x \(\frac{1}{2}\)) x 3
= \(\frac{3}{8}\)
8
If 30% of y is equal to x, what in terms of x, is 30% of 3y?
A
\(\frac{x}{9}\)
B
\(\frac{x}{3}\)
C
x
D
3x
9
A baker used 40% of a 50kg bag of flour. If \(\frac{1}{8}\) of the amount used was for the cake, how many kilogram of flour was used for the cake?
A
2\(\frac{1}{2}\)
B
6\(\frac{1}{2}\)
C
15\(\frac{3}{8}\)
D
17\(\frac{1}{2}\)
correct option: a
\(\frac{40}{100} \times 50\)kg = 20kg
\(\frac{1}{8}\) of 20kg for cake; \(\frac{1}{8}\) x \(\frac{20}{1}\)
= 2\(\frac{1}{2}\)kg
Users' Answers & Comments\(\frac{1}{8}\) of 20kg for cake; \(\frac{1}{8}\) x \(\frac{20}{1}\)
= 2\(\frac{1}{2}\)kg
10
If tan y = 0.404, where y is acute, find cos 2y
A
0.035
B
0.719
C
0.808
D
0.927
correct option: b
tan y = 0.404; y = tan-1 0.0404(tables);y = 22o
cos 2y = cos 2(22o); cos 44o
= 0.719
Users' Answers & Commentscos 2y = cos 2(22o); cos 44o
= 0.719