Adam and Charlie have some stickers in the ratio of 7 : 4.
When Adam gives away 74 stickers,
the ratio of the stickers becomes 3 : 7.
- How many stickers do they have at first?
- How many stickers do they have in the end?
|
Adam |
Charlie |
Before |
7 x 7 = 49 u |
4 x 7 = 28 u |
Change |
- 74 |
No change |
After |
3 x 4 = 12 u |
7 x 4 = 28 u |
(a)
The number of stickers that Charlie has remains unchanged.
Make the number of stickers that Charlie has the same using LCM of 4 and 7.
LCM of 4 and 7 = 28
Number of stickers that Adam gives away
= 49 u - 12 u
= 37 u
37 u = 74
1 u = 74 ÷ 37 = 2
Number of stickers that they have at first
= 49 u + 28 u
= 77 u
= 77 x 2
= 154
(b)
Number of stickers that they have in the end
= 12 u + 28 u
= 40 u
= 40 x 2
= 80
Answer(s): (a) 154; (b) 80