19 Primary 1 students and 14 of Primary 2 students went on a school excursion. The number of Primary 2 girls was 3 times the number of Primary 1 girls, and there were 13 more Primary 1 boys than Primary 2 boys. How many less Primary 2 boys than Primary 2 girls went on the school excursion?
Primary 1 |
Primary 2 |
19 |
14 |
Girls |
Boys |
Girls |
Boys |
1 u |
1 p + 13 |
3 u |
1 p |
Total number of students in Primary 1 = 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 2 = 3 u + 1 p
3 u + 1 p = 14 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 14 - 6
3 u - 1 u = 8
2 u = 8
1 u = 8 ÷ 2 = 4
Number of girls in Primary 2
= 3 u
= 3 x 4
= 12
Number of boys in Primary 2
= 1 p
= 14 - 3 u
= 14 - 12
= 2
Number of less boys than girls in Primary 2
= 12 - 2
= 10
Answer(s): 10