1999 - WAEC Mathematics Past Questions and Answers - page 4
Amina had m mangoes. She ate 3 and shared the remainder equally with her brother Uche. Each had at least 10. Which of the following inequalities represents the statements above.
Total number of mangoes = m
Amina ate 3 mangoes \(\implies\) Remainder = m - 3
Shared equally with Uche \(\implies \frac{m - 3}{2}\)
\(\frac{m - 3}{2} \geq 10\)
If \(x^2 +15x + 50 = ax^2 + bx + c = 0\). Which of the following statement is not true?
\(x^2 + 15x + 50 = 0\)
\(x^2 + 5x + 10x + 50 = 0\)
\(x(x + 5) + 10(x + 5) = 0\)
\((x + 5)(x + 10) = 0\)
x + 5 = 0 or x + 10 = 0.
Comparing \(x^2 + 15x + 50\) with \(ax^2 + bx + c\), b = 15 and c = 50.
\(\therefore\) bc = 750.
The root of a quadratic equation in x, are -m and 2n. Find the equation
x = -m \(\implies\) x + m = 0;
x = 2n \(\implies\) x - 2n = 0.
\(\implies (x + m)(x - 2n) = 0\)
\(x^2 + mx - 2nx - 2mn = 0\)
\(x^2 + x(m - 2n) - 2mn = 0\)
A survey shows that 28% of all the men in a village wear size 9 shoes. What is the probability that a man selected at random in the village wears size 9 shoes?
P(man picked at random wears size 9 shoes) = \(\frac{28}{100}\)
= \(\frac{7}{25}\)
xy + xCE = xy + y^2\
∴xCE = y^2\
CE=\frac{y^2}{x}\)