Isn't it 250% loss in buying value? So because of inflation everything now cost 2,5x what it did. Usually your paycheck can afford 100 apples but after inflation your paycheck can only afford 40.

If you had money for 100 apples, and now you only have money for 40 apples, you're down 60%, not 250%.

Sure, but that was not the claim by the parent. It's a bit unintuitive the way the parent wrote the claim, but the parent said the currency lost its value by 250% which is not really possible. What I think the parent means is that it became 2,5 times less worth. That is, what before could buy 100 apples can now buy 40 apples since 100/1=100 and 100/2,5=40, and as you say it, that means the value is down by 60% - same thing. At least that is how I understand what the parent claimed.