22 Primary 4 students and 16 of Primary 5 students went on a school excursion. The number of Primary 5 boys was 3 times the number of Primary 4 boys, and there were 14 less Primary 5 girls than Primary 4 girls. How many less Primary 5 girls than Primary 5 boys went on the school excursion?
| Primary 4 |
Primary 5 |
| 22 |
16 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 14 |
3 u |
1 p |
Total number of students in Primary 4 = 1 u + 1 p + 14
1 u + 1 p + 14 = 22
1 u + 1 p = 22 - 14
1 u + 1 p = 8 --- (1)
Total number of students in Primary 5 = 3 u + 1 p
3 u + 1 p = 16 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 16 - 8
3 u - 1 u = 8
2 u = 8
1 u = 8 ÷ 2 = 4
Number of boys in Primary 5
= 3 u
= 3 x 4
= 12
Number of girls in Primary 5
= 1 p
= 16 - 3 u
= 16 - 12
= 4
Number of less girls than boys in Primary 5
= 12 - 4
= 8
Answer(s): 8
