Risa's mother's weight to her weight is 7 : 5. If Risa puts on 25% more weight, by what percentage must her mother's weight be reduced by so that their total weight remains unchanged as before? Correct the answer to 1 decimal place.
| |
Risa's mother |
Risa |
Total |
| Before |
7 u |
5 u |
12 u |
| Change |
- 1.25 u |
+ 1.25 u |
|
| After |
5.75 u |
6.25 u |
12 u |
Amount of weight that Risa puts on
= 25% x 5 u
=
25100 x 5 u
= 1.25 u
The total weight remains unchanged.
Percentage of weight that Risa's mother must be reduced by
=
1.257 x 100%
≈ 17.9% (Correct to 1 decimal place.)
Answer(s): 17.9%
