25 Primary 4 students and 22 of Primary 5 students went on a school excursion. The number of Primary 5 boys was 4 times the number of Primary 4 boys, and there were 15 more Primary 4 girls than Primary 5 girls. How many more Primary 5 boys than Primary 5 girls went on the school excursion?
| Primary 4 |
Primary 5 |
| 25 |
22 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 15 |
4 u |
1 p |
Total number of students in Primary 4 = 1 u + 1 p + 15
1 u + 1 p + 15 = 25
1 u + 1 p = 25 - 15
1 u + 1 p = 10 --- (1)
Total number of students in Primary 5 = 4 u + 1 p
4 u + 1 p = 22 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 22 - 10
4 u - 1 u = 12
3 u = 12
1 u = 12 ÷ 3 = 4
Number of boys in Primary 5
= 4 u
= 4 x 4
= 16
Number of girls in Primary 5
= 1 p
= 22 - 4 u
= 22 - 16
= 6
Number of more boys than girls in Primary 5
= 16 - 6
= 10
Answer(s): 10
