The ratio of the number of green stickers to red stickers is 3 : 1.
After Adam buys 30 green stickers and 90 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 |
+ 30 |
+ 90 |
After |
3 u + 30 |
1 u + 90 |
The number of green stickers and red stickers are equal in the end.
3 u + 30 = 1 u + 90
3 u - 1 u = 90 - 30
2 u = 60
1 u = 60 ÷ 2 = 30
Number of stickers that Adam has now
= 3 u + 30 + 1 u + 90
= 3 u + 1 u + 30 + 90
= 4 u + 120
= 4 x 30 + 120
= 120 + 120
= 240
Answer(s): 240