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