Risa and Isaac had an equal number of mochi balls at first. After Risa bought another 8 mochi balls and Isaac lost 20 mochi balls, Risa had five times as many mochi balls as Isaac. Find the number of mochi balls each of them had at first.
| |
Risa |
Isaac |
| Before |
5 u - 8 |
1 u + 20 |
| Change |
+ 8 |
- 20 |
| After |
5 u |
1 u |
The number of mochi balls that Risa and Isaac at first is the same.
5 u - 8 = 1 u + 20
5 u - 1 u = 20 + 8
4 u = 28
1 u = 28 ÷ 4 = 7
Number of mochi balls that each of them had at first
= 1 u + 20
= 7 + 20
= 27
Answer(s): 27
