Tammy and Lucy have some stickers. If Tammy gives 18 stickers to Lucy, Lucy will have 5 times the number of stickers as Tammy. If Lucy gives 72 stickers to Tammy, Tammy will have
25 as many stickers as Lucy. How many stickers does Tammy have at first?
|
Case 1 |
Case 2 |
|
Tammy |
Lucy |
Tammy |
Lucy |
Before |
7 u + 18 |
35 u - 18 |
12 u - 72 |
30 u + 72 |
Change |
- 18 |
+ 18 |
+ 72 |
- 72 |
After |
1x7 = 7 u |
5x7 = 35 u |
2x6 = 12 u |
5x6 = 30 u |
The total number of stickers in both cases remains unchanged. Make the total number of stickers in both cases the same. LCM of 6 and 7 is 42.
Number of stickers that Tammy had at first is the same in both cases.
12 u - 72 = 7 u + 18
12 u - 7 u = 18 + 72
5 u = 90
1 u = 18
Number of stickers that Tammy had at first
= 7 u + 18
= 7 x 18 + 18
= 126 + 18
= 144
Answer(s): 144