Yesterday, Mae had 31 local and foreign stamps. Today, she gave away
13 of her local stamps and 6 of her foreign stamps. Now, she has an equal number of local and foreign stamps. How many local stamps did she have yesterday?
|
Local stamps |
Foreign stamps |
Total |
Before |
3 u |
2 u + 6 |
31 |
Change |
- 1 u |
- 6 |
|
After |
2 u |
2 u |
|
Mae has an equal number of local and foreign stamps in the end.
Total number of stamps yesterday
= 3 u + 2 u + 6
= 5 u + 6
5 u + 6 = 31
5 u = 31 - 6
5 u = 25
1 u = 25 ÷ 5 = 5
Number of local stamps yesterday
= 3 u
= 3 x 5
= 15
Answer(s): 15