Cathy gave 3 erasers to every girl and 6 erasers to every boy in her class. There were 7 more girls than boys in the class. She gave away a total of 129 erasers.
- How many children were there in the class?
- How many less erasers were given to the girls than the boys?
(a)
There were more girls than boys in class.
If we remove the 7 extra girls, the number of girls and boys will be the same.
Cathy would give away less erasers.
Number of less erasers that Cathy needed to give away if there was 7 less girls
= 7 x 3
= 21
Number of erasers she would need if there was 7 less girls
= 129 - 21
= 108
Number of erasers to give for every 1 girl and 1 boy
= 3 + 6
= 9
Number of sets of 1 girl and 1 boy
= 108 ÷ 9
= 12
Number of boys = 12
Number of girls
= 12 + 7
= 19
Number of children
= 12 + 19
= 31
(b)
Number of erasers given to the girls
= 19 x 3
= 57
Number of erasers given to the boys
= 12 x 6
= 72
Number of less erasers given to the girls than the boys
= 72 - 57
= 15
Answer(s): (a) 31; (b) 15
