39 Primary 1 students and 35 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 19 more Primary 1 girls than Primary 2 girls. How many less Primary 2 girls than Primary 2 boys went on the school camp?
Primary 1 |
Primary 2 |
39 |
35 |
Boys |
Girls |
Boys |
Girls |
1 u |
1 p + 19 |
4 u |
1 p |
Total number of students in Primary 1 = 1 u + 1 p + 19
1 u + 1 p + 19 = 39
1 u + 1 p = 39 - 19
1 u + 1 p = 20 --- (1)
Total number of students in Primary 2 = 4 u + 1 p
4 u + 1 p = 35 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 35 - 20
4 u - 1 u = 15
3 u = 15
1 u = 15 ÷ 3 = 5
Number of boys in Primary 2
= 4 u
= 4 x 5
= 20
Number of girls in Primary 2
= 1 p
= 35 - 4 u
= 35 - 20
= 15
Number of less girls than boys in Primary 2
= 20 - 15
= 5
Answer(s): 5