22 Primary 3 students and 12 of Primary 4 students went on a school learning journey. The number of Primary 4 boys was 5 times the number of Primary 3 boys, and there were 18 more Primary 3 girls than Primary 4 girls. How many less Primary 4 girls than Primary 4 boys went on the school learning journey?
| Primary 3 |
Primary 4 |
| 22 |
12 |
| Boys |
Girls |
Boys |
Girls |
| 1 u |
1 p + 18 |
5 u |
1 p |
Total number of students in Primary 3 = 1 u + 1 p + 18
1 u + 1 p + 18 = 22
1 u + 1 p = 22 - 18
1 u + 1 p = 4 --- (1)
Total number of students in Primary 4 = 5 u + 1 p
5 u + 1 p = 12 --- (2)
(2) - (1)
(5 u + 1 p) - (1 u + 1 p) = 12 - 4
5 u - 1 u = 8
4 u = 8
1 u = 8 ÷ 4 = 2
Number of boys in Primary 4
= 5 u
= 5 x 2
= 10
Number of girls in Primary 4
= 1 p
= 12 - 5 u
= 12 - 10
= 2
Number of less girls than boys in Primary 4
= 10 - 2
= 8
Answer(s): 8
