The question is wrong. They should have worded it as asking for a quarter of the bars remaining not the remaining quarter. 16-4 is 12 and a quarter of 16 is 4. So what is a remaining quarter? Is it of the original amount that the first quarter was taking from? Or is it a quarter of the remaining amount? The remaining amount wasn't quartered but they're still asking for the quartered amount without indicating which amount was supposedly quartered. Logically the only amount that was quartered was 16 therefore she must be asking for an additional quarter (4) giving her half the total amount. So now she's taken 8 candy bars from Rachel. She deserves a slap.
But then if it's a quarter from the original quantity, there is no use for the word "remaining" at all? I took it as "remaining['s] quarter", so 3 additional bars.
Anyways that's too much and I agree with your conclusion.
Anyways that's too much and I agree with your conclusion.