The ratio of the number of red stickers to green stickers is 3 : 1.
After Adam buys 20 red stickers and 50 green stickers,
there is an equal number of red stickers and green stickers.
How many stickers does Adam have now?
|
Red |
Green |
Before |
3 u |
1 u |
Change |
+ 20 |
+ 50 |
After |
3 u + 20 |
1 u + 50 |
The number of red stickers and green stickers are equal in the end.
3 u + 20 = 1 u + 50
3 u - 1 u = 50 - 20
2 u = 30
1 u = 30 ÷ 2 = 15
Number of stickers that Adam has now
= 3 u + 20 + 1 u + 50
= 3 u + 1 u + 20 + 50
= 4 u + 70
= 4 x 15 + 70
= 60 + 70
= 130
Answer(s): 130