1100 boys and 700 girls are examined in a test; 42\% of the boys and 30\% of the girls pass. The percentage of the total who failed is
(a)58\%
(b)$62 \frac{2}{3} \%$
(c)64\%
(d)78\%
Answer
Answer (as printed):
Explanation
Total number of students $=1100+700=1800$. Number of students passed = (42\% of 1100 + 30\% of 700) $$=(462+210)=672 .$$ Number of failures $=1800-672=1128$. $$\text { ∴ } \text { Percentage failure }=\left(\frac{1128}{1800} \times 100\right) \%=62 \frac{2}{3} \% .$$
Explanation as extracted from the printed page; notation may be imperfect.