23 Primary 5 students and 18 of Primary 6 students went on a school learning journey. The number of Primary 6 girls was 4 times the number of Primary 5 girls, and there were 17 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 |
23 |
18 |
Girls |
Boys |
Girls |
Boys |
1 u |
1 p + 17 |
4 u |
1 p |
Total number of students in Primary 5 = 1 u + 1 p + 17
1 u + 1 p + 17 = 23
1 u + 1 p = 23 - 17
1 u + 1 p = 6 --- (1)
Total number of students in Primary 6 = 4 u + 1 p
4 u + 1 p = 18 --- (2)
(2) - (1)
(4 u + 1 p) - (1 u + 1 p) = 18 - 6
4 u - 1 u = 12
3 u = 12
1 u = 12 ÷ 3 = 4
Number of girls in Primary 6
= 4 u
= 4 x 4
= 16
Number of boys in Primary 6
= 1 p
= 18 - 4 u
= 18 - 16
= 2
Number of less boys than girls in Primary 6
= 16 - 2
= 14
Answer(s): 14