19 Primary 4 students and 16 of Primary 5 students went on a school oversea trip. The number of Primary 5 girls was 3 times the number of Primary 4 girls, and there were 13 more Primary 4 boys than Primary 5 boys. How many more Primary 5 girls than Primary 5 boys went on the school oversea trip?
Primary 4 |
Primary 5 |
19 |
16 |
Girls |
Boys |
Girls |
Boys |
1 u |
1 p + 13 |
3 u |
1 p |
Total number of students in Primary 4 = 1 u + 1 p + 13
1 u + 1 p + 13 = 19
1 u + 1 p = 19 - 13
1 u + 1 p = 6 --- (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 - 6
3 u - 1 u = 10
2 u = 10
1 u = 10 ÷ 2 = 5
Number of girls in Primary 5
= 3 u
= 3 x 5
= 15
Number of boys in Primary 5
= 1 p
= 16 - 3 u
= 16 - 15
= 1
Number of more girls than boys in Primary 5
= 15 - 1
= 14
Answer(s): 14