22 Primary 5 students and 16 of Primary 6 students went on a school learning journey. The number of Primary 6 girls was 3 times the number of Primary 5 girls, and there were 12 less Primary 6 boys than Primary 5 boys. How many less Primary 6 boys than Primary 6 girls went on the school learning journey?
Primary 5 |
Primary 6 |
22 |
16 |
Girls |
Boys |
Girls |
Boys |
1 u |
1 p + 12 |
3 u |
1 p |
Total number of students in Primary 5 = 1 u + 1 p + 12
1 u + 1 p + 12 = 22
1 u + 1 p = 22 - 12
1 u + 1 p = 10 --- (1)
Total number of students in Primary 6 = 3 u + 1 p
3 u + 1 p = 16 --- (2)
(2) - (1)
(3 u + 1 p) - (1 u + 1 p) = 16 - 10
3 u - 1 u = 6
2 u = 6
1 u = 6 ÷ 2 = 3
Number of girls in Primary 6
= 3 u
= 3 x 3
= 9
Number of boys in Primary 6
= 1 p
= 16 - 3 u
= 16 - 9
= 7
Number of less boys than girls in Primary 6
= 9 - 7
= 2
Answer(s): 2