Ans is D

Let say scarf’s price is 39 and hat’s price is 1.

My doubt is - she purchased both for 40 and she received a discount of 25% on scarf. So the original price for scarf will be 39/0.75=52. So savings for scarf will be 52-39 = 13. Is this approach correct?

I saw someone solving it like 39*0.25= savings = 9.75 for scarf.

Which is the correct approach and what is the reason why my approach is wrong.