Adam and Bryan have some stickers in the ratio of 3 : 8.
When Adam buys another 42 stickers,
the ratio of the stickers becomes 5 : 4.
- How many stickers do they have at first?
- How many stickers do they have in the end?
|
Adam |
Charlie |
Before |
3 x 1 = 3 u |
8 x 1 = 8 u |
Change |
+ 42 |
No change |
After |
5 x 2 = 10 u |
4 x 2 = 8 u |
(a)
The number of stickers that Charlie has remains unchanged.
Make the number of stickers that Charlie has the same using LCM of 8 and 4.
LCM of 8 and 4 = 8
Number of stickers that Adam buys
= 10 u - 3 u
= 7 u
7 u = 42
1 u = 42 ÷ 7 = 6
Number of stickers that they have at first
= 3 u + 8 u
= 11 u
= 11 x 6
= 66
(b)
Number of stickers that they have in the end
= 10 u + 8 u
= 18 u
= 18 x 6
= 108
Answer(s): (a) 66; (b) 108