39 Primary 4 students and 34 of Primary 5 students went on a school outing. The number of Primary 5 boys was 3 times the number of Primary 4 boys, and there were 17 more Primary 4 girls than Primary 5 girls. How many more Primary 5 boys than Primary 5 girls went on the school outing?
| Primary 4 |
Primary 5 |
| 39 |
34 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 17 |
3 u |
1 p |
Total number of students in Primary 4 = 1 u + 1 p + 17
1 u + 1 p + 17 = 39
1 u + 1 p = 39 - 17
1 u + 1 p = 22 --- (1)
Total number of students in Primary 5 = 3 u + 1 p
3 u + 1 p = 34 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 34 - 22
3 u - 1 u = 12
2 u = 12
1 u = 12 ÷ 2 = 6
Number of boys in Primary 5
= 3 u
= 3 x 6
= 18
Number of girls in Primary 5
= 1 p
= 34 - 3 u
= 34 - 18
= 16
Number of more boys than girls in Primary 5
= 18 - 16
= 2
Answer(s): 2
