The ratio of the number of blue stickers to red stickers is 9 : 7.
After Adam gives away 30 blue stickers and 10 red stickers,
there is an equal number of blue stickers and red stickers.
How many stickers does Adam have now?
|
Blue |
Red |
Before |
9 u |
7 u |
Change |
- 30 |
- 10 |
After |
9 u - 30 |
7 u - 10 |
The number of blue stickers and red stickers in the end is the same.
9 u - 30 = 7 u - 10
9 u - 7 u = 30 - 10
2 u = 20
1 u = 20 ÷ 2 = 10
Number of stickers that Adam has now
= 9 u - 30 + 7 u - 10
= 9 u + 7 u - 30 - 10
= 16 u - 40
= 16 x 10 - 40
= 160 - 40
= 120
Answer(s): 120