The number of blue and red stickers are equal.
If Adam gives away 90 blue stickers and 30 red stickers,
the ratio of blue stickers to red stickers becomes 4 : 7.
How many stickers are there at first?
|
Blue |
Red |
Before |
4 u + 90 |
7 u + 30 |
Change |
- 90 |
- 30 |
After |
4 u |
7 u |
The number of blue and red stickers is the same at first.
4 u + 90 = 7 u + 30
7 u - 4 u = 90 - 30
3 u = 60
1 u = 60 ÷ 3 = 20
Number of stickers that Adam has at first
= 4 u + 90 + 7 u + 30
= 4 u + 7 u + 90 + 30
= 11 u + 120
= 11 x 20 + 120
= 220 + 120
= 340
Answer(s): 340