Risa had 45 as many erasers as Vanessa. The sum of the number of erasers Risa and Vanessa had was the same as the number of erasers that Usha had. After trading, Usha gave 30% of her erasers to Risa and received 20% of Vanessa's erasers. After that, Vanessa continued to trade and increased her number of erasers in the end by 20%, find the ratio of her number of erasers to the sum of Risa's and Usha's erasers in the end.
| |
Risa |
Usha |
Vanessa |
Total |
| Before |
4 u |
9 u |
5 u |
18 u |
| Change 1 |
+ 2.7 u |
- 2.7 u |
|
|
| Change 2 |
|
+ 1 u |
- 1 u |
|
| After 1 |
6.7 u |
7.3 u |
4 u |
|
| Change 3 |
- 0.8 u |
+ 0.8 u |
|
| After 2 |
13.2 u |
4.8 u |
18 u |
Total number of erasers that Risa and Vanessa had at first
= 4 u + 5 u
= 9 u
Number of erasers that Usha had at first = 9 u
Number of erasers that Usha gave to Risa
= 30% x 9 u
=
30100 x 4 u
= 2.7 u
Number of erasers that Usha received from Vanessa
= 20% x 5 u
=
20100 x 5 u
= 1 u
Number of erasers that Vanessa increased by when she continued to trade
= 20% x 4 u
=
20100 x 4 u
= 0.8 u
Number of erasers that Risa and Usha had in the end
= 6.7 u + 7.3 u - 0.8 u
= 13.2 u
In the end
Vanessa : Risa and Usha
4.8 : 13.2
480 : 1320
4 : 11
Answer(s): 4 : 11
