25 Primary 1 students and 15 of Primary 2 students went on a school excursion. The number of Primary 2 boys was 4 times the number of Primary 1 boys, and there were 16 more Primary 1 girls than Primary 2 girls. How many less Primary 2 girls than Primary 2 boys went on the school excursion?
Primary 1 |
Primary 2 |
25 |
15 |
Boys |
Girls |
Boys |
Girls |
1 u |
1 p + 16 |
4 u |
1 p |
Total number of students in Primary 1 = 1 u + 1 p + 16
1 u + 1 p + 16 = 25
1 u + 1 p = 25 - 16
1 u + 1 p = 9 --- (1)
Total number of students in Primary 2 = 4 u + 1 p
4 u + 1 p = 15 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 15 - 9
4 u - 1 u = 6
3 u = 6
1 u = 6 ÷ 3 = 2
Number of boys in Primary 2
= 4 u
= 4 x 2
= 8
Number of girls in Primary 2
= 1 p
= 15 - 4 u
= 15 - 8
= 7
Number of less girls than boys in Primary 2
= 8 - 7
= 1
Answer(s): 1