29 Primary 1 students and 22 of Primary 2 students went on a school oversea trip. The number of Primary 2 boys was 4 times the number of Primary 1 boys, and there were 19 less Primary 2 girls than Primary 1 girls. How many less Primary 2 girls than Primary 2 boys went on the school oversea trip?
Primary 1 |
Primary 2 |
29 |
22 |
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 = 29
1 u + 1 p = 29 - 19
1 u + 1 p = 10 --- (1)
Total number of students in Primary 2 = 4 u + 1 p
4 u + 1 p = 22 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 22 - 10
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
= 22 - 4 u
= 22 - 16
= 6
Number of less girls than boys in Primary 2
= 16 - 6
= 10
Answer(s): 10