Mrs Chau gave Mary and Usha some money each on Wednesday. On Thursday, Mary gave
14 of the amount she had to Usha. On Friday, Usha gave
13 of the amount she had to Mary. In the end, Mary had $40 and Usha had $20. How much did Usha had more than Mary at first?
| |
Mary |
Usha |
Total |
| Before 1 |
4 u |
? |
$60 |
| Change 1 |
- 1 u |
+ 1 u |
|
| After 1 |
3 u |
3 p |
$60 |
| Before 2 |
$40 - 1 p |
3 p |
$60 |
| Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$40 |
2 p
($20) |
$60 |
Amount that Usha had in the end = 2 p
2 p = 20
1 p = 20 ÷ 2 = 10
Working backwards.
Amount that Mary had after giving to Usha on Thursday
= 40 - 1 p
= 40 - 10
= $30
3 u = 30
1 u = 30 ÷ 3 = 10
Amount that Mary had at first
= 4 u
= 4 x 10
= $40
Total amount that Mary and Usha had
= 40 + 20
= $60
Amount that Usha had at first
= 60 - 40
= $20
Amount that Mary had more than Usha
= 40 - 20
= $20
Answer(s): $20
