20% of the pupils are girls. 50% of the girls and 70% of the boys wear spectacles. What percentage of the pupils do not wear spectacles?
Girls |
Boys |
Total |
20% |
80% |
100% |
Wear spectacles |
Do not wear |
Wear spectacles |
Do not wear |
|
10% |
10% |
56% |
24% |
100% |
Number of girls who wear spectacles
= 50% x 20%
=
50100 x 20%
= 10%
Number of boys who wear spectacles
= 70% x 80%
=
70100 x 80%
= 56%
Percentage of pupils who wear spectacles
= 10% + 56%
= 66%
Percentage of pupils who do not wear spectacles
= 100% - 66%
= 34%
Answer: 34%