Betty's and Winnie's savings were in the ratio of 4 : 9. Both of them shared the cost of their cousin's present equally. Betty's remaining savings was ²₅ as much as Winnie's savings. What percentage of her savings did Betty spend? Correct the answer to 1 decimal place.

	Betty	Winnie	Difference
Before	4x3 = 12 u	9x3 = 27 u	5x3 = 15 u
Change	- 2 u	- 2 u
After	2x5 = 10 u	5x5 = 25 u	3x5 = 15 u

Since Betty and Winnie shared the cost of their cousin's present equally, the amount each paid for the present is the same. 

So, the difference in the amounts between Betty and Winnie at first and in the end remains the same.  Make the difference in the amounts between Betty and Winnie at first and in the end the same. LCM of 5 and 3 is 15.

Amount that Betty spent on the present
= 12 u - 10 u
= 2 u

Percentage of her savings that Betty spent
= ²₁₂ x 100%
≈ 16.7%

Answer(s): 16.7%