Adam has 90 blue stickers and 300 red stickers.
After buying the same number of stickers,
the ratio of the blue stickers and the red stickers becomes 3 : 8.
How many stickers does he buy?
|
Blue |
Red |
Difference |
Before |
90 |
300 |
210 |
Change |
+ ? |
+ ? |
|
After |
3 u |
8 u |
5 u |
At first
Difference in the number of stickers
= 300 - 90
= 210
In the end
Number of blue stickers = 3 u
Number of red stickers = 8 u
Difference in the number of stickers in units
= 8 u - 3 u
= 5 u
The difference in the number of stickers between the blue stickers and the red stickers remains unchanged.
5 u = 210
1 u = 210 ÷ 5 = 42
Number of blue stickers that Adam buys
= 3 u - 90
= 3 x 42 - 90
= 126 - 90
= 36
Total number of stickers that Adam buys
= 2 x 36
= 72
Answer(s): 72