Risa's and Emma's savings were in the ratio of 4 : 9. Both of them shared the cost of their younger sister's present equally. Risa's remaining savings was ¹₅ as much as Emma's savings. What percentage of her savings did Risa spend? Correct the answer to 1 decimal place.

	Risa	Emma	Difference
Before	4x4 = 16 u	9x4 = 36 u	5x4 = 20 u
Change	- 11 u	- 11 u
After	1x5 = 5 u	5x5 = 25 u	4x5 = 20 u

Since Risa and Emma shared the cost of their younger sister's present equally, the amount each paid for the present is the same. 

So, the difference in the amounts between Risa and Emma at first and in the end remains the same.  Make the difference in the amounts between Risa and Emma at first and in the end the same. LCM of 5 and 4 is 20.

Amount that Risa spent on the present
= 16 u - 5 u
= 11 u

Percentage of her savings that Risa spent
= ¹¹₁₆ x 100%
≈ 68.8%

Answer(s): 68.8%