Joelle and Erika had an equal number of stamps at first. Joelle used
13 of her stamps and Erika used
19 of her stamps. They used 8 stamps altogether. How many stamps did Erika have in the end?
| |
Joelle |
Erika |
| Before |
3x3 =
9 u |
9x1 =
9 u |
| Change |
- 1x3 =
- 3 u |
- 1x1 =
- 1 u |
| After |
2x3 =
6 u |
8x1 =
8 u |
The number of stamps that Joelle and Erika each had at first is the same. Make the number of stamps that Joelle and Erika each had at first the same. LCM of 3 and 9 is 9.
Number of stamps that Joelle and Erika used
= 3 u + 1 u
= 4 u
4 u = 8
1 u = 8 ÷ 4 = 2
Number of stamps that Erika had in the end
= 8 u
= 8 x 2
= 16
Answer(s): 16
