Jean and Erika have some cupcakes each. If Jean gives Erika 30 cupcakes, Jean will have
58 as many cupcakes as Erika. If Jean gives Erika 2 cupcakes, they will have an equal number of cupcakes. How many cupcakes does Erika have at first?
|
Case 1 |
Case 2 |
|
Jean |
Erika |
Jean |
Erika |
Before |
5 u + 30 |
8 u - 30 |
6.5 u + 2 |
6.5 u - 2 |
Change |
- 30 |
+ 30 |
- 2 |
+ 2 |
After |
5 u |
8 u |
6.5 u |
6.5 u |
Total number of cupcakes that Jean and Erika have
= 5 u + 8 u
= 13 u
Number of cupcakes that Jean and Erika each has in the end is the same.
Number of cupcakes that Jean and Erika each has in the end in Case 2
= 13 u ÷ 2
= 6.5 u
Number of cupcakes that Jean had at first is the same in Case 1 and Case 2.
6.5 u + 2 = 5 u + 30
6.5 u - 5 u = 30 - 2
0.5 u = 28
1 u = 28 ÷ 0.5 = 56
Number of cupcakes that Erika has
= 8 u - 30
= 8 x 56 - 30
= 448 - 30
= 418
Answer(s): 418