Bobby had 100 more coins than Gabriel. Bobby gave 25% of his coins to Gabriel. Gabriel in return gave 80% of his coins to Bobby. In the end, Bobby had 250 more coins than Gabriel. How many coins did Bobby have at first?
| |
Bobby |
Gabriel |
Comparing Bobby
and Peter at first |
100 more |
|
| Before |
4 u + 100 |
4 u |
| Change 1 |
- 1 u - 25 |
+ 1 u + 25 |
| After 1 |
3 u + 75 |
5 u + 25 |
| Change 2 |
+ 4 u + 20 |
- 4 u - 20 |
| After 2 |
7 u + 95 |
1 u + 5 |
25% =
25100 =
1425% x 100
=
25100 x 100
= 25
80% x 25
=
80100 x 25
= 20
80% x 5 u
=
80100 x 5 u
= 4 u
Bobby had 250 more coins than Gabriel in the end. If another 250 coins are given to Gabriel, both will have the same number of coins.
7 u + 95 = 1 u + 5 + 250
7 u - 1 u = 5 + 250 - 95
4 u = 160
1 u = 160 ÷ 4 = 40
Number of Bobby's coins at first
= 4 u + 100
= 4 x 40 + 100
= 160 + 100
= 260
Answer: 260
