70% of the pupils are girls. 30% of the girls and 40% of the boys wear watches. What percentage of the pupils do not wear watches?
Girls |
Boys |
Total |
70% |
30% |
100% |
Wear watches |
Do not wear |
Wear watches |
Do not wear |
|
21% |
49% |
12% |
18% |
100% |
Number of girls who wear watches
= 30% x 70%
=
30100 x 70%
= 21%
Number of boys who wear watches
= 40% x 30%
=
40100 x 30%
= 12%
Percentage of pupils who wear watches
= 21% + 12%
= 33%
Percentage of pupils who do not wear watches
= 100% - 33%
= 67%
Answer: 67%