Mary gave 5 marbles to every boy and 10 marbles to every girl in her class. There were 7 more boys than girls in the class. She gave away a total of 185 marbles.
- How many children were there in the class?
- How many less marbles were given to the boys than the girls?
(a)
There were more boys than girls in class.
If we remove the 7 extra boys, the number of boys and girls will be the same.
Mary would give away less marbles.
Number of less marbles that Mary needed to give away if there was 7 less boys
= 7 x 5
= 35
Number of marbles she would need if there was 7 less boys
= 185 - 35
= 150
Number of marbles to give for every 1 boy and 1 girl
= 5 + 10
= 15
Number of sets of 1 boy and 1 girl
= 150 ÷ 15
= 10
Number of girls = 10
Number of boys
= 10 + 7
= 17
Number of children
= 10 + 17
= 27
(b)
Number of marbles given to the boys
= 17 x 5
= 85
Number of marbles given to the girls
= 10 x 10
= 100
Number of less marbles given to the boys than the girls
= 100 - 85
= 15
Answer(s): (a) 27; (b) 15
