80% of the pupils are boys. 30% of the boys and 40% of the girls wear watches. What percentage of the pupils do not wear watches?
| Boys |
Girls |
Total |
| 80% |
20% |
100% |
| Wear watches |
Do not wear |
Wear watches |
Do not wear |
|
| 24% |
56% |
8% |
12% |
100% |
Number of boys who wear watches
= 30% x 80%
=
30100 x 80%
= 24%
Number of girls who wear watches
= 40% x 20%
=
40100 x 20%
= 8%
Percentage of pupils who wear watches
= 24% + 8%
= 32%
Percentage of pupils who do not wear watches
= 100% - 32%
= 68%
Answer: 68%
