Erika's and Abi's savings were in the ratio of 4 : 7. Both of them shared the cost of their older sister's present equally. Erika's remaining savings was ¹₃ as much as Abi's savings. What percentage of her savings did Abi spend? Correct the answer to 1 decimal place.

	Erika	Abi	Difference
Before	4x2 = 8 u	7x2 = 14 u	3x2 = 6 u
Change	- 5 u	- 5 u
After	1x3 = 3 u	3x3 = 9 u	2x3 = 6 u

Since Erika and Abi shared the cost of their older sister's present equally, the amount each paid for the present is the same. 

So, the difference in the amounts between Erika and Abi at first and in the end remains the same.  Make the difference in the amounts between Erika and Abi at first and in the end the same. LCM of 3 and 2 is 6.

Amount that Abi spent on the present
= 14 u - 9 u
= 5 u

Percentage of her savings that Abi spent
= ⁵₁₄ x 100%
≈ 35.7%

Answer(s): 35.7%