Yen and Rachel have some cookies each. If Yen gives Rachel 27 cookies, Yen will have
27 as many cookies as Rachel. If Yen gives Rachel 4 cookies, they will have an equal number of cookies. How many cookies does Rachel have at first?
|
Case 1 |
Case 2 |
|
Yen |
Rachel |
Yen |
Rachel |
Before |
2 u + 27 |
7 u - 27 |
4.5 u + 4 |
4.5 u - 4 |
Change |
- 27 |
+ 27 |
- 4 |
+ 4 |
After |
2 u |
7 u |
4.5 u |
4.5 u |
Total number of cookies that Yen and Rachel have
= 2 u + 7 u
= 9 u
Number of cookies that Yen and Rachel each has in the end is the same.
Number of cookies that Yen and Rachel each has in the end in Case 2
= 9 u ÷ 2
= 4.5 u
Number of cookies that Yen had at first is the same in Case 1 and Case 2.
4.5 u + 4 = 2 u + 27
4.5 u - 2 u = 27 - 4
0.5 u = 23
1 u = 23 ÷ 0.5 = 46
Number of cookies that Rachel has
= 7 u - 27
= 7 x 46 - 27
= 322 - 27
= 295
Answer(s): 295