John had 70 more coins than Peter. John gave 20% of his coins to Peter. Peter in return gave 50% of his coins to John. In the end, John had 156 more coins than Peter. How many coins did John have at first?
| |
John |
Peter |
Comparing John
and Peter at first |
70 more |
|
| Before |
5 u + 70 |
5 u |
| Change 1 |
- 1 u - 14 |
+ 1 u + 14 |
| After 1 |
4 u + 56 |
6 u + 14 |
| Change 2 |
+ 3 u + 7 |
- 3 u - 7 |
| After 2 |
7 u + 63 |
3 u + 7 |
20% =
20100 =
1520% x 70
=
20100 x 70
= 14
50% x 14
=
50100 x 14
= 7
50% x 6 u
=
50100 x 6 u
= 3 u
John had 156 more coins than Peter in the end. If another 156 coins are given to Peter, both will have the same number of coins.
7 u + 63 = 3 u + 7 + 156
7 u - 3 u = 7 + 156 - 63
4 u = 100
1 u = 100 ÷ 4 = 25
Number of John's coins at first
= 5 u + 70
= 5 x 25 + 70
= 125 + 70
= 195
Answer: 195
