50% of the pupils are boys. 60% of the boys and 70% of the girls wear watches. What percentage of the pupils do not wear watches?
| Boys |
Girls |
Total |
| 50% |
50% |
100% |
| Wear watches |
Do not wear |
Wear watches |
Do not wear |
|
| 30% |
20% |
35% |
15% |
100% |
Number of boys who wear watches
= 60% x 50%
=
60100 x 50%
= 30%
Number of girls who wear watches
= 70% x 50%
=
70100 x 50%
= 35%
Percentage of pupils who wear watches
= 30% + 35%
= 65%
Percentage of pupils who do not wear watches
= 100% - 65%
= 35%
Answer: 35%
