90% of the pupils are boys. 60% of the boys and 70% of the girls wear spectacles. What percentage of the pupils do not wear spectacles?
| Boys |
Girls |
Total |
| 90% |
10% |
100% |
| Wear spectacles |
Do not wear |
Wear spectacles |
Do not wear |
|
| 54% |
36% |
7% |
3% |
100% |
Number of boys who wear spectacles
= 60% x 90%
=
60100 x 90%
= 54%
Number of girls who wear spectacles
= 70% x 10%
=
70100 x 10%
= 7%
Percentage of pupils who wear spectacles
= 54% + 7%
= 61%
Percentage of pupils who do not wear spectacles
= 100% - 61%
= 39%
Answer: 39%
