30 Primary 1 pupils and 26 of Primary 2 pupils went on a school camp. The number of Primary 2 boys was 3 times the number of Primary 1 boys, and there were 20 more Primary 1 girls than Primary 2 girls. How many less Primary 2 girls than Primary 2 boys went on the school camp?
| Primary 1 |
Primary 2 |
| 30 |
26 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 20 |
3 u |
1 p |
Total number of pupils in Primary 1 = 1 u + 1 p + 20
1 u + 1 p + 20 = 30
1 u + 1 p = 30 - 20
1 u + 1 p = 10 --- (1)
Total number of pupils in Primary 2 = 3 u + 1 p
3 u + 1 p = 26 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 26 - 10
3 u - 1 u = 16
2 u = 16
1 u = 16 ÷ 2 = 8
Number of boys in Primary 2
= 3 u
= 3 x 8
= 24
Number of girls in Primary 2
= 1 p
= 26 - 3 u
= 26 - 24
= 2
Number of less girls than boys in Primary 2
= 24 - 2
= 22
Answer(s): 22
