20 students share some stickers.
Each boy gets 2 stickers.
Each girl gets 3 stickers.
In total, the boys get 15 more stickers than the girls.
- How many girls are there?
- How many boys are there?
- How many stickers do the girls get?
- How many stickers do the children get?
Number of boys |
Total stickers that the boys get |
Number of girls |
Total stickers that the girls get |
More stickers for the boys than the girls |
20 |
20 x 2 = 40 |
0 |
0 x 3 = 0 |
40 - 0 = 40 |
19 |
19 x 2 = 38 |
1 |
1 x 3 = 3 |
38 - 3 = 35 |
15 |
15 x 2 = 30 |
5 |
5 x 3 = 15 |
30 - 15 = 15 |
(a)
Number of more stickers for the boys than the girls if all the students are boys,
= 20 x 2
= 40
Number of more stickers for the boys than the girls if one boy is replaced by a girl
= 19 x 2 - 1 x 3
= 38 - 3
= 35
Big difference in the decrease in the number of stickers when a boy is replaced by a girl
= 40 - 15
= 25
Small difference in the decrease in the number of stickers when a boy is replaced by a girl
= 2 + 3
= 5
Number of girls
= 25 ÷ 5
= 5
(b)
Number of boys
= 20 - 5
= 15
(c)
Number of stickers that the girls get
= 5 x 3
= 15
(d)
Number of stickers that the boys get
= 15 x 2
= 30
Total number of stickers
= 15 + 30
= 45
Answer(s): (a) 5; (b) 15; (c) 15; (d) 45