Peter had 20% more marbles than Sean. Peter gave 30% of his marbles to Sean. Sean in return gave 50% of his marbles to Peter. In the end, Sean had 504 less marbles than Peter. How many marbles did Peter have at first?
| |
Peter |
Sean |
| Before |
120% |
100% |
| Change 1 |
- 36% |
+ 36% |
| After 1 |
84% |
136% |
| Change 2 |
+ 68% |
- 68% |
| After 2 |
152% |
68% |
Number of marbles that Peter had at first in percent
= 100% + 20%
= 120%
Number of marbles that Peter gave to Sean in percent
= 30% x 120%
=
30100 x 120%
= 36%
Number of marbles that Sean gave to Peter in percent
= 50% x 136%
=
50100 x 136%
= 68%
Number of less marbles that Sean had than Peter in the end
= 152% - 68%
= 84%
84% → 504
1% → 504 ÷ 84 = 6
Number of marbles that Peter had at first
= 120%
= 120 x 6
= 720
Answer(s): 720
