There are some pupils in the school hall.
35 of them are girls, of whom 20% of them do not wear watches.
12 of the boys do not wear watches. What is the percentage of the pupils in the school hall who do not wear watches?
| Girls |
Boys |
Total |
3x5 =
15 u |
2x5 =
10 u |
5x5 =
25 u |
| No watches |
Watches |
No watches |
Watches |
|
| 1x3 |
4x3 |
1x5 |
1x5 |
|
| 3 u |
12 u |
5 u |
5 u |
25 u |
20% =
20100=
15 The number of girls is the repeated identity. Make the number of girls the same. LCM of 3 and 5 is 15.
Number of pupils who do not wear watches
= 3 u + 5 u
= 8 u
Total number of pupils
= 3 u + 12 u + 5 u + 5 u
= 25 u
Percentage of the pupils in the school hall who do not wear watches
=
825 x 100%
= 32%
Answer(s): 32%
