34 Primary 1 students and 31 of Primary 2 students went on a school camp. The number of Primary 2 boys was 4 times the number of Primary 1 boys, and there were 15 less Primary 2 girls than Primary 1 girls. How many less Primary 2 girls than Primary 2 boys went on the school camp?
| Primary 1 |
Primary 2 |
| 34 |
31 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 15 |
4 u |
1 p |
Total number of students in Primary 1 = 1 u + 1 p + 15
1 u + 1 p + 15 = 34
1 u + 1 p = 34 - 15
1 u + 1 p = 19 --- (1)
Total number of students in Primary 2 = 4 u + 1 p
4 u + 1 p = 31 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 31 - 19
4 u - 1 u = 12
3 u = 12
1 u = 12 ÷ 3 = 4
Number of boys in Primary 2
= 4 u
= 4 x 4
= 16
Number of girls in Primary 2
= 1 p
= 31 - 4 u
= 31 - 16
= 15
Number of less girls than boys in Primary 2
= 16 - 15
= 1
Answer(s): 1
