30 Primary 4 students and 23 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 15 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 |
30 |
23 |
Boys |
Girls |
Boys |
Girls |
1 u |
1 p + 15 |
3 u |
1 p |
Total number of students in Primary 4 = 1 u + 1 p + 15
1 u + 1 p + 15 = 30
1 u + 1 p = 30 - 15
1 u + 1 p = 15 --- (1)
Total number of students in Primary 5 = 3 u + 1 p
3 u + 1 p = 23 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 23 - 15
3 u - 1 u = 8
2 u = 8
1 u = 8 ÷ 2 = 4
Number of boys in Primary 5
= 3 u
= 3 x 4
= 12
Number of girls in Primary 5
= 1 p
= 23 - 3 u
= 23 - 12
= 11
Number of more boys than girls in Primary 5
= 12 - 11
= 1
Answer(s): 1