25 Primary 2 students and 22 of Primary 3 students went on a school outing. The number of Primary 3 girls was 5 times the number of Primary 2 girls, and there were 15 more Primary 2 boys than Primary 3 boys. How many less Primary 3 boys than Primary 3 girls went on the school outing?
Primary 2 |
Primary 3 |
25 |
22 |
Girls |
Boys |
Girls |
Boys |
1 u |
1 p + 15 |
5 u |
1 p |
Total number of students in Primary 2 = 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 3 = 5 u + 1 p
5 u + 1 p = 22 --- (2)
(2) - (1)
(5 u + 1 p) - (1 u + 1 p) = 22 - 10
5 u - 1 u = 12
4 u = 12
1 u = 12 ÷ 4 = 3
Number of girls in Primary 3
= 5 u
= 5 x 3
= 15
Number of boys in Primary 3
= 1 p
= 22 - 5 u
= 22 - 15
= 7
Number of less boys than girls in Primary 3
= 15 - 7
= 8
Answer(s): 8