Adam and Bryan have some stickers in the ratio of 6 : 5.
When Adam buys another 21 stickers,
the ratio of the stickers becomes 3 : 2.
- How many stickers do they have at first?
- How many stickers do they have in the end?
|
Adam |
Charlie |
Before |
6 x 2 = 12 u |
5 x 2 = 10 u |
Change |
+ 21 |
No change |
After |
3 x 5 = 15 u |
2 x 5 = 10 u |
(a)
The number of stickers that Charlie has remains unchanged.
Make the number of stickers that Charlie has the same using LCM of 5 and 2.
LCM of 5 and 2 = 10
Number of stickers that Adam buys
= 15 u - 12 u
= 3 u
3 u = 21
1 u = 21 ÷ 3 = 7
Number of stickers that they have at first
= 12 u + 10 u
= 22 u
= 22 x 7
= 154
(b)
Number of stickers that they have in the end
= 15 u + 10 u
= 25 u
= 25 x 7
= 175
Answer(s): (a) 154; (b) 175