Yesterday, Mae had 110 local and foreign stamps. Today, she gave away
15 of her local stamps and 20 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 + 20 |
110 |
| Change |
- 1 u |
- 20 |
|
| 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 + 20
= 9 u + 20
9 u + 20 = 110
9 u = 110 - 20
9 u = 90
1 u = 90 ÷ 9 = 10
Number of local stamps yesterday
= 5 u
= 5 x 10
= 50
Answer(s): 50
