There are some pupils in the school hall.
110 of them are boys, of whom 80% of them do not wear watches.
29 of the girls do not wear watches. What is the percentage of the pupils in the school hall who wear watches?
| Boys |
Girls |
Total |
1x5 =
5 u |
9x5 =
45 u |
10x5 =
50 u |
| No watches |
Watches |
No watches |
Watches |
|
| 4x1 |
1x1 |
2x5 |
7x5 |
|
| 4 u |
1 u |
10 u |
35 u |
50 u |
80% =
80100=
45 The number of boys is the repeated identity. Make the number of boys the same. LCM of 1 and 5 is 5.
Number of pupils who wear watches
= 1 u + 35 u
= 36 u
Total number of pupils
= 4 u + 1 u + 10 u + 35 u
= 50 u
Percentage of the pupils in the school hall who wear watches
=
3650 x 100%
= 72%
Answer(s): 72%
