Jane and Cindy have some cookies each. If Jane gives Cindy 9 cookies, Jane will have
45 as many cookies as Cindy. If Jane gives Cindy 4 cookies, they will have an equal number of cookies. How many cookies does Jane have at first?
| |
Case 1 |
Case 2 |
| |
Jane |
Cindy |
Jane |
Cindy |
| Before |
4 u + 9 |
5 u - 9 |
4.5 u + 4 |
4.5 u - 4 |
| Change |
- 9 |
+ 9 |
- 4 |
+ 4 |
| After |
4 u |
5 u |
4.5 u |
4.5 u |
Total number of cookies that Jane and Cindy have
= 4 u + 5 u
= 9 u
Number of cookies that Jane and Cindy each has in the end is the same.
Number of cookies that Jane and Cindy each has in the end in Case 2
= 9 u ÷ 2
= 4.5 u
Number of cookies that Jane had at first is the same in Case 1 and Case 2.
4.5 u + 4 = 4 u + 9
4.5 u - 4 u = 9 - 4
0.5 u = 5
1 u = 5 ÷ 0.5 = 10
Number of cookies that Jane has
= 4 u + 9
= 4 x 10 + 9
= 40 + 9
= 49
Answer(s): 49
