18 Primary 2 students and 14 of Primary 3 students went on a school excursion. The number of Primary 3 girls was 4 times the number of Primary 2 girls, and there were 10 less Primary 3 boys than Primary 2 boys. How many less Primary 3 boys than Primary 3 girls went on the school excursion?
| Primary 2 |
Primary 3 |
| 18 |
14 |
| Girls |
Boys |
Girls |
Boys |
| 1 u |
1 p + 10 |
4 u |
1 p |
Total number of students in Primary 2 = 1 u + 1 p + 10
1 u + 1 p + 10 = 18
1 u + 1 p = 18 - 10
1 u + 1 p = 8 --- (1)
Total number of students in Primary 3 = 4 u + 1 p
4 u + 1 p = 14 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 14 - 8
4 u - 1 u = 6
3 u = 6
1 u = 6 ÷ 3 = 2
Number of girls in Primary 3
= 4 u
= 4 x 2
= 8
Number of boys in Primary 3
= 1 p
= 14 - 4 u
= 14 - 8
= 6
Number of less boys than girls in Primary 3
= 8 - 6
= 2
Answer(s): 2
