The ratio of the number of green stickers to red stickers is 3 : 1.
After Adam buys 40 green stickers and 80 red stickers,
there is an equal number of green stickers and red stickers.
How many stickers does Adam have now?
| |
Green |
Red |
| Before |
3 u |
1 u |
| Change |
+ 40 |
+ 80 |
| After |
3 u + 40 |
1 u + 80 |
The number of green stickers and red stickers are equal in the end.
3 u + 40 = 1 u + 80
3 u - 1 u = 80 - 40
2 u = 40
1 u = 40 ÷ 2 = 20
Number of stickers that Adam has now
= 3 u + 40 + 1 u + 80
= 3 u + 1 u + 40 + 80
= 4 u + 120
= 4 x 20 + 120
= 80 + 120
= 200
Answer(s): 200
