The ratio of the number of red stickers to blue stickers is 8 : 1.
After Adam buys another 90 red stickers and 90 blue stickers,
the ratio of the number of red stickers to blue stickers is 7 : 2.
How many stickers does Adam have now?
|
Red |
Blue |
Difference |
Before |
8 x 5 = 40 u |
1 x 5 = 5 u |
7 x 5 = 35 u |
Change |
+ 90 |
+ 90 |
|
After |
7 x 7 = 49 u |
2 x 7 = 14 u |
5 x 7 = 35 u |
The difference in the number of red stickers and blue stickers is the same.
Make the difference in the number of red stickers and blue stickers the same using the LCM of 7 and 5.
LCM of 7 and 5 = 35
Number of red stickers that Adam buys
= 49 u - 40 u
= 9 u
9 u = 90
1 u = 90 ÷ 9 = 10
Number of stickers that Adam has now
= 49 u + 14 u
= 63 u
= 63 x 10
= 630
Answer(s): 630