20 students share some stickers.
Each girl gets 3 stickers.
Each boy gets 4 stickers.
In total, the girls get 11 more stickers than the boys.
- How many boys are there?
- How many girls are there?
- How many stickers do the boys get?
- How many stickers do the children get?
Number of girls |
Total stickers that the girls get |
Number of boys |
Total stickers that the boys get |
More stickers for the girls than the boys |
20 |
20 x 3 = 60 |
0 |
0 x 4 = 0 |
60 - 0 = 60 |
19 |
19 x 3 = 57 |
1 |
1 x 4 = 4 |
57 - 4 = 53 |
13 |
13 x 3 = 39 |
7 |
7 x 4 = 28 |
39 - 28 = 11 |
(a)
Number of more stickers for the girls than the boys if all the students are girls,
= 20 x 3
= 60
Number of more stickers for the girls than the boys if one girl is replaced by a boy
= 19 x 3 - 1 x 4
= 57 - 4
= 53
Big difference in the decrease in the number of stickers when a girl is replaced by a boy
= 60 - 11
= 49
Small difference in the decrease in the number of stickers when a girl is replaced by a boy
= 3 + 4
= 7
Number of boys
= 49 ÷ 7
= 7
(b)
Number of girls
= 20 - 7
= 13
(c)
Number of stickers that the boys get
= 7 x 4
= 28
(d)
Number of stickers that the girls get
= 13 x 3
= 39
Total number of stickers
= 28 + 39
= 67
Answer(s): (a) 7; (b) 13; (c) 28; (d) 67