Gem and Kathy had an equal number of stamps at first. Gem used
14 of her stamps and Kathy used
110 of her stamps. They used 21 stamps altogether. How many stamps did Kathy have in the end?
|
Gem |
Kathy |
Before |
4x5 = 20 u |
10x2 = 20 u |
Change |
- 1x5 = - 5 u |
- 1x2 = - 2 u |
After |
3x5 = 15 u |
9x2 = 18 u |
The number of stamps that Gem and Kathy each had at first is the same. Make the number of stamps that Gem and Kathy each had at first the same. LCM of 4 and 10 is 20.
Number of stamps that Gem and Kathy used
= 5 u + 2 u
= 7 u
7 u = 21
1 u = 21 ÷ 7 = 3
Number of stamps that Kathy had in the end
= 18 u
= 18 x 3
= 54
Answer(s): 54