Yesterday, Mae had 31 local and foreign stamps. Today, she gave away
15 of her local stamps and 4 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 |
5 u |
4 u + 4 |
31 |
Change |
- 1 u |
- 4 |
|
After |
4 u |
4 u |
|
Mae has an equal number of local and foreign stamps in the end.
Total number of stamps yesterday
= 5 u + 4 u + 4
= 9 u + 4
9 u + 4 = 31
9 u = 31 - 4
9 u = 27
1 u = 27 ÷ 9 = 3
Number of local stamps yesterday
= 5 u
= 5 x 3
= 15
Answer(s): 15