29 Primary 2 pupils and 25 of Primary 3 pupils went on a school learning journey. The number of Primary 3 girls was 3 times the number of Primary 2 girls, and there were 20 more Primary 2 boys than Primary 3 boys. How many more Primary 3 girls than Primary 3 boys went on the school learning journey?
| Primary 2 |
Primary 3 |
| 29 |
25 |
| Girls |
Boys |
Girls |
Boys |
| 1 u |
1 p + 20 |
3 u |
1 p |
Total number of pupils in Primary 2 = 1 u + 1 p + 20
1 u + 1 p + 20 = 29
1 u + 1 p = 29 - 20
1 u + 1 p = 9 --- (1)
Total number of pupils in Primary 3 = 3 u + 1 p
3 u + 1 p = 25 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 25 - 9
3 u - 1 u = 16
2 u = 16
1 u = 16 ÷ 2 = 8
Number of girls in Primary 3
= 3 u
= 3 x 8
= 24
Number of boys in Primary 3
= 1 p
= 25 - 3 u
= 25 - 24
= 1
Number of more girls than boys in Primary 3
= 24 - 1
= 23
Answer(s): 23
