There are some pupils in the school hall.
310 of them are girls, of whom 70% of them do not wear hats.
37 of the boys do not wear hats. What is the percentage of the pupils in the school hall who wear hats?
Girls |
Boys |
Total |
3x10 = 30 u |
7x10 = 70 u |
10x10 = 100 u |
No hats |
Hats |
No hats |
Hats |
|
7x3 |
3x3 |
3x10 |
4x10 |
|
21 u |
9 u |
30 u |
40 u |
100 u |
70% =
70100=
710 The number of girls is the repeated identity. Make the number of girls the same. LCM of 3 and 10 is 30.
Number of pupils who wear hats
= 9 u + 40 u
= 49 u
Total number of pupils
= 21 u + 9 u + 30 u + 40 u
= 100 u
Percentage of the pupils in the school hall who wear hats
=
49100 x 100%
= 49%
Answer(s): 49%