The ratio of the number of red stickers to blue stickers is 3 : 1.
After Adam buys 20 red stickers and 80 blue stickers,
there is an equal number of red stickers and blue stickers.
How many stickers does Adam have now?
|
Red |
Blue |
Before |
3 u |
1 u |
Change |
+ 20 |
+ 80 |
After |
3 u + 20 |
1 u + 80 |
The number of red stickers and blue stickers are equal in the end.
3 u + 20 = 1 u + 80
3 u - 1 u = 80 - 20
2 u = 60
1 u = 60 ÷ 2 = 30
Number of stickers that Adam has now
= 3 u + 20 + 1 u + 80
= 3 u + 1 u + 20 + 80
= 4 u + 100
= 4 x 30 + 100
= 120 + 100
= 220
Answer(s): 220