Yesterday, Mae had 78 local and foreign stamps. Today, she gave away
15 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 |
5 u |
4 u + 6 |
78 |
| Change |
- 1 u |
- 6 |
|
| 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 + 6
= 9 u + 6
9 u + 6 = 78
9 u = 78 - 6
9 u = 72
1 u = 72 ÷ 9 = 8
Number of local stamps yesterday
= 5 u
= 5 x 8
= 40
Answer(s): 40
