There was an equal number of purple and red balls in a box at first. After 27 red balls were taken out and 27 purple balls were added into the box, there was
17 as many red balls as purple balls. Find the number of red balls in the box at first.
|
Purple balls |
Red balls |
Before |
7 u - 27 |
1 u + 27 |
Change |
+ 27 |
- 27 |
After |
7 u |
1 u |
The number of purple and red balls in the box is the same at first.
7 u - 27 = 1 u + 27
7 u - 1 u = 27 + 27
6 u = 54
1 u = 54 ÷ 6 = 9
Number of red balls at first
= 1 u + 27
= 9 + 27
= 36
Answer(s)36