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 :

Answer: Option B

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
∴ Percentage failure :
= $$\left(\frac{1128}{1800}\times 100\right)\%$$
= $$62\frac{2}{3}\%$$