1997 - WAEC Mathematics Past Questions and Answers - page 1
If P = {3, 5, 6} and Q = {4, 5, 6} then P∩Q equals
Let x represent the intersection
34 - x + 22 - x + x = 49
- x = 49 - 56; x = 7
A student found the approximate value of 0.02548 correct to two places of decimal instead of two significant figures. Find the percentage error.
0.02548 \(\approxeq\) 0.03 (to 2 decimal places)
0.02548 \(\approxeq\) 0.025 (2 sig. figs)
Error = 0.03 - 0.025
= 0.005
% error = \(\frac{0.005}{0.025} \times 100%\)
= 20%
Users' Answers & Comments
2/3 (x + 5) = 1/4(5x - 3)
8x + 40 = 15x - 9
-7x = -49
x = 7
Which of the following equations has its roots as 4 and -5?
(x - 4)(x + 5) = 0
x\(^2\) + 5x - 4x - 20 = 0
x\(^2\) + x - 20 = 0
Solve the equations: 4x -y = 11; 5x + 2y = 4.
4x - y = 11....(1) x 2 8x - 2y = 22....(3)
5x + 12y = 4....(2) x 1 5x + 2y = 4....(4)
add eqn (3) and (4)
13x = 26
x = 2
4(2) - y = 11 \(\implies\) y = 8 - 11
y = -3.
Users' Answers & Commentsq(p - r3) = rt2
P α 1/w2; P = K/W2
9 = K/42; 9 = K/16
K = 9 x 16 = 144
P = K/W2; when w = 9
P = 144/92 = 144/81 = 16/9