The ratio of the number of red stickers to blue stickers is 7 : 3.
After Adam buys 30 red stickers and 90 blue stickers,
there is an equal number of red stickers and blue stickers.
How many stickers does Adam have now?
|
Red |
Blue |
Before |
7 u |
3 u |
Change |
+ 30 |
+ 90 |
After |
7 u + 30 |
3 u + 90 |
The number of red stickers and blue stickers are equal in the end.
7 u + 30 = 3 u + 90
7 u - 3 u = 90 - 30
4 u = 60
1 u = 60 ÷ 4 = 15
Number of stickers that Adam has now
= 7 u + 30 + 3 u + 90
= 7 u + 3 u + 30 + 90
= 10 u + 120
= 10 x 15 + 120
= 150 + 120
= 270
Answer(s): 270