There are some pupils in the school hall.
310 of them are girls, of whom 20% of them do not wear caps.
27 of the boys do not wear caps. What is the percentage of the pupils in the school hall who do not wear caps?
Girls |
Boys |
Total |
3x5 = 15 u |
7x5 = 35 u |
10x5 = 50 u |
No caps |
Caps |
No caps |
Caps |
|
1x3 |
4x3 |
2x5 |
5x5 |
|
3 u |
12 u |
10 u |
25 u |
50 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 caps
= 3 u + 10 u
= 13 u
Total number of pupils
= 3 u + 12 u + 10 u + 25 u
= 50 u
Percentage of the pupils in the school hall who do not wear caps
=
1350 x 100%
= 26%
Answer(s): 26%