Risa had $345 more than Yen. Risa gave
23 of her money to Yen. Yen then gave 20% of her money to Risa. In the end, Yen had $223 more than Risa. How much did Risa have at first?
| |
Risa |
Yen |
Comparing Risa
and Yen at first |
345 more |
|
| Before |
3 u |
+ 345 |
3 u |
|
| Change 1 |
- 2 u |
- 230 |
+ 2 u |
+ 230 |
| After 1 |
1 u |
+ 115 |
5 u |
+ 230 |
| Change 2 |
+ 1 u |
+ 46 |
- 1 u |
- 46 |
| After 2 |
2 u |
+ 161 |
4 u |
+ 184 |
23 x 345= 230
345 - 230 = 115
20% x 5 u
=
20100 x 5 u
= 1 u
20% x 230
=
20100 x 230
= 46
230 - 46 = 184
115 + 46 = 161
If Risa received another $223 in the end, Risa and Yen would have the same amount of money.
4 u + 184 = 2 u + 161 + 223
4 u - 2 u = 161 + 223 - 184
2 u = 200
1 u = 200 ÷ 2 = 100
Amount that Risa had at first
= 3 u + 345
= 3 x 100 + 345
= 300 + 345
= $645
Answer(s): $645
