19 Primary 3 pupils and 15 of Primary 4 pupils went on a school learning journey. The number of Primary 4 boys was 5 times the number of Primary 3 boys, and there were 12 more Primary 3 girls than Primary 4 girls. How many more Primary 4 boys than Primary 4 girls went on the school learning journey?
| Primary 3 |
Primary 4 |
| 19 |
15 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 12 |
5 u |
1 p |
Total number of pupils in Primary 3 = 1 u + 1 p + 12
1 u + 1 p + 12 = 19
1 u + 1 p = 19 - 12
1 u + 1 p = 7 --- (1)
Total number of pupils in Primary 4 = 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 4
= 5 u
= 5 x 2
= 10
Number of girls in Primary 4
= 1 p
= 15 - 5 u
= 15 - 10
= 5
Number of more boys than girls in Primary 4
= 10 - 5
= 5
Answer(s): 5
