The number of red and blue stickers are equal.
If Adam gives away 70 red stickers and 30 blue stickers,
the ratio of red stickers to blue stickers becomes 2 : 7.
How many stickers are there at first?
|
Red |
Blue |
Before |
2 u + 70 |
7 u + 30 |
Change |
- 70 |
- 30 |
After |
2 u |
7 u |
The number of red and blue stickers is the same at first.
2 u + 70 = 7 u + 30
7 u - 2 u = 70 - 30
5 u = 40
1 u = 40 ÷ 5 = 8
Number of stickers that Adam has at first
= 2 u + 70 + 7 u + 30
= 2 u + 7 u + 70 + 30
= 9 u + 100
= 9 x 8 + 100
= 72 + 100
= 172
Answer(s): 172