Barbara and Roshel have some muffins each. If Barbara gives Roshel 31 muffins, Barbara will have
23 as many muffins as Roshel. If Barbara gives Roshel 3 muffins, they will have an equal number of muffins. How many muffins does Roshel have at first?
|
Case 1 |
Case 2 |
|
Barbara |
Roshel |
Barbara |
Roshel |
Before |
2 u + 31 |
3 u - 31 |
2.5 u + 3 |
2.5 u - 3 |
Change |
- 31 |
+ 31 |
- 3 |
+ 3 |
After |
2 u |
3 u |
2.5 u |
2.5 u |
Total number of muffins that Barbara and Roshel have
= 2 u + 3 u
= 5 u
Number of muffins that Barbara and Roshel each has in the end is the same.
Number of muffins that Barbara and Roshel each has in the end in Case 2
= 5 u ÷ 2
= 2.5 u
Number of muffins that Barbara had at first is the same in Case 1 and Case 2.
2.5 u + 3 = 2 u + 31
2.5 u - 2 u = 31 - 3
0.5 u = 28
1 u = 28 ÷ 0.5 = 56
Number of muffins that Roshel has
= 3 u - 31
= 3 x 56 - 31
= 168 - 31
= 137
Answer(s): 137