Yesterday, Mae had 61 local and foreign stamps. Today, she gave away
15 of her local stamps and 7 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 + 7 |
61 |
Change |
- 1 u |
- 7 |
|
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 + 7
= 9 u + 7
9 u + 7 = 61
9 u = 61 - 7
9 u = 54
1 u = 54 ÷ 9 = 6
Number of local stamps yesterday
= 5 u
= 5 x 6
= 30
Answer(s): 30