A group of pupils took part in a survey to vote for their favourite sport. Each pupil voted for only 1 type of sport: aerobics, gymnastics or swimming.
47 of them voted for either aerobics or gymnastics.
23 of them for either gymnastics or swimming. 35 of them voted for gymnastics. How many pupils took part in the survey?
| Aerobics |
Gymnastics |
Swimming |
Total |
| 4x3 |
3x3 |
7x3 |
| 1x7 |
2x7 |
3x7 |
| 7 u |
5 u |
9 u |
21 u |
The total number of pupils is unchanged. Make the total number of pupils the same. LCM of 7 and 3 is 21.
Number of pupils who voted for gymnastics = 5 u
5 u = 35
1 u = 35 ÷ 5 = 7
Total number of pupils who took part in the survey
= 21 u
= 21 x 7
= 147
Answer(s): 147
