37 Primary 4 pupils and 34 of Primary 5 pupils went on a school excursion. The number of Primary 5 girls was 4 times the number of Primary 4 girls, and there were 18 more Primary 4 boys than Primary 5 boys. How many more Primary 5 girls than Primary 5 boys went on the school excursion?
| Primary 4 |
Primary 5 |
| 37 |
34 |
| Girls |
Boys |
Girls |
Boys |
| 1 u |
1 p + 18 |
4 u |
1 p |
Total number of pupils in Primary 4 = 1 u + 1 p + 18
1 u + 1 p + 18 = 37
1 u + 1 p = 37 - 18
1 u + 1 p = 19 --- (1)
Total number of pupils in Primary 5 = 4 u + 1 p
4 u + 1 p = 34 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 34 - 19
4 u - 1 u = 15
3 u = 15
1 u = 15 ÷ 3 = 5
Number of girls in Primary 5
= 4 u
= 4 x 5
= 20
Number of boys in Primary 5
= 1 p
= 34 - 4 u
= 34 - 20
= 14
Number of more girls than boys in Primary 5
= 20 - 14
= 6
Answer(s): 6
