There was an equal number of red and purple marbles in a bag at first. After 21 purple marbles were taken out and 23 red marbles were added into the bag, there was
13 as many purple marbles as red marbles. Find the number of purple marbles in the bag at first.
|
Red marbles |
Purple marbles |
Before |
3 u - 23 |
1 u + 21 |
Change |
+ 23 |
- 21 |
After |
3 u |
1 u |
The number of red and purple marbles in the bag is the same at first.
3 u - 23 = 1 u + 21
3 u - 1 u = 21 + 23
2 u = 44
1 u = 44 ÷ 2 = 22
Number of purple marbles at first
= 1 u + 21
= 22 + 21
= 43
Answer(s)43