25 Primary 5 pupils and 22 of Primary 6 pupils went on a school learning journey. The number of Primary 6 girls was 4 times the number of Primary 5 girls, and there were 18 more Primary 5 boys than Primary 6 boys. How many more Primary 6 girls than Primary 6 boys went on the school learning journey?
| Primary 5 |
Primary 6 |
| 25 |
22 |
| Girls |
Boys |
Girls |
Boys |
| 1 u |
1 p + 18 |
4 u |
1 p |
Total number of pupils in Primary 5 = 1 u + 1 p + 18
1 u + 1 p + 18 = 25
1 u + 1 p = 25 - 18
1 u + 1 p = 7 --- (1)
Total number of pupils in Primary 6 = 4 u + 1 p
4 u + 1 p = 22 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 22 - 7
4 u - 1 u = 15
3 u = 15
1 u = 15 ÷ 3 = 5
Number of girls in Primary 6
= 4 u
= 4 x 5
= 20
Number of boys in Primary 6
= 1 p
= 22 - 4 u
= 22 - 20
= 2
Number of more girls than boys in Primary 6
= 20 - 2
= 18
Answer(s): 18
