41 Primary 3 students and 34 of Primary 4 students went on a school excursion. The number of Primary 4 girls was 3 times the number of Primary 3 girls, and there were 19 more Primary 3 boys than Primary 4 boys. How many more Primary 4 girls than Primary 4 boys went on the school excursion?
Primary 3 |
Primary 4 |
41 |
34 |
Girls |
Boys |
Girls |
Boys |
1 u |
1 p + 19 |
3 u |
1 p |
Total number of students in Primary 3 = 1 u + 1 p + 19
1 u + 1 p + 19 = 41
1 u + 1 p = 41 - 19
1 u + 1 p = 22 --- (1)
Total number of students in Primary 4 = 3 u + 1 p
3 u + 1 p = 34 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 34 - 22
3 u - 1 u = 12
2 u = 12
1 u = 12 ÷ 2 = 6
Number of girls in Primary 4
= 3 u
= 3 x 6
= 18
Number of boys in Primary 4
= 1 p
= 34 - 3 u
= 34 - 18
= 16
Number of more girls than boys in Primary 4
= 18 - 16
= 2
Answer(s): 2