18 Primary 1 pupils and 15 of Primary 2 pupils went on a school trip. The number of Primary 2 boys was 5 times the number of Primary 1 boys, and there were 11 more Primary 1 girls than Primary 2 girls. How many more Primary 2 boys than Primary 2 girls went on the school trip?
| Primary 1 |
Primary 2 |
| 18 |
15 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 11 |
5 u |
1 p |
Total number of pupils in Primary 1 = 1 u + 1 p + 11
1 u + 1 p + 11 = 18
1 u + 1 p = 18 - 11
1 u + 1 p = 7 --- (1)
Total number of pupils in Primary 2 = 5 u + 1 p
5 u + 1 p = 15 --- (2)
(2) - (1)
(5 u + 1 p) - (1 u + 1 p) = 15 - 7
5 u - 1 u = 8
4 u = 8
1 u = 8 ÷ 4 = 2
Number of boys in Primary 2
= 5 u
= 5 x 2
= 10
Number of girls in Primary 2
= 1 p
= 15 - 5 u
= 15 - 10
= 5
Number of more boys than girls in Primary 2
= 10 - 5
= 5
Answer(s): 5
