90% of the pupils are boys. 50% of the boys and 70% of the girls wear watches. What percentage of the pupils do not wear watches?
Boys |
Girls |
Total |
90% |
10% |
100% |
Wear watches |
Do not wear |
Wear watches |
Do not wear |
|
45% |
45% |
7% |
3% |
100% |
Number of boys who wear watches
= 50% x 90%
=
50100 x 90%
= 45%
Number of girls who wear watches
= 70% x 10%
=
70100 x 10%
= 7%
Percentage of pupils who wear watches
= 45% + 7%
= 52%
Percentage of pupils who do not wear watches
= 100% - 52%
= 48%
Answer: 48%