Fanny and Kathy have some macarons each. If Fanny gives Kathy 17 macarons, Fanny will have
23 as many macarons as Kathy. If Fanny gives Kathy 2 macarons, they will have an equal number of macarons. How many macarons does Kathy have at first?
|
Case 1 |
Case 2 |
|
Fanny |
Kathy |
Fanny |
Kathy |
Before |
2 u + 17 |
3 u - 17 |
2.5 u + 2 |
2.5 u - 2 |
Change |
- 17 |
+ 17 |
- 2 |
+ 2 |
After |
2 u |
3 u |
2.5 u |
2.5 u |
Total number of macarons that Fanny and Kathy have
= 2 u + 3 u
= 5 u
Number of macarons that Fanny and Kathy each has in the end is the same.
Number of macarons that Fanny and Kathy each has in the end in Case 2
= 5 u ÷ 2
= 2.5 u
Number of macarons that Fanny had at first is the same in Case 1 and Case 2.
2.5 u + 2 = 2 u + 17
2.5 u - 2 u = 17 - 2
0.5 u = 15
1 u = 15 ÷ 0.5 = 30
Number of macarons that Kathy has
= 3 u - 17
= 3 x 30 - 17
= 90 - 17
= 73
Answer(s): 73