Erika and Emily have some cupcakes each. If Erika gives Emily 23 cupcakes, Erika will have
14 as many cupcakes as Emily. If Erika gives Emily 10 cupcakes, they will have an equal number of cupcakes. How many cupcakes does Emily have at first?
|
Case 1 |
Case 2 |
|
Erika |
Emily |
Erika |
Emily |
Before |
1 u + 23 |
4 u - 23 |
2.5 u + 10 |
2.5 u - 10 |
Change |
- 23 |
+ 23 |
- 10 |
+ 10 |
After |
1 u |
4 u |
2.5 u |
2.5 u |
Total number of cupcakes that Erika and Emily have
= 1 u + 4 u
= 5 u
Number of cupcakes that Erika and Emily each has in the end is the same.
Number of cupcakes that Erika and Emily each has in the end in Case 2
= 5 u ÷ 2
= 2.5 u
Number of cupcakes that Erika had at first is the same in Case 1 and Case 2.
2.5 u + 10 = 1 u + 23
2.5 u - 1 u = 23 - 10
0.5 u = 13
1 u = 13 ÷ 0.5 = 26
Number of cupcakes that Emily has
= 4 u - 23
= 4 x 26 - 23
= 104 - 23
= 81
Answer(s): 81