Erika and Dana shared a box of stamps. Erika had 90% of the total stamps. if Erika gave 280 of her stamps to Dana, both would have the same number of stamps. How many stamps did Erika have?
| |
Erika |
Dana |
Total |
| Before |
90% |
10% |
100% |
| Change |
- 40% |
+ 40% |
|
| After |
50% |
50% |
100% |
Total number of stamps that Erika and Dana shared = 100%
If Erika gave 280 stamps to Dana, both would have the same number of stamps.
Number of stamps that each would have in the end
= 100% ÷ 2
= 50%
Number of stamps that Erika gave to Dana
= 90% - 50%
= 40%
40% → 280
1% → 280 ÷ 40 = 7
Number of stamps that Erika had
= 90%
= 90 x 7
= 630
Answer(s): 630
