It should be asking for how much longer it takes for Hunter to clean his house, since it says 3 and 1/2 hours. Jeremy only takes 2 and a half hour to clean, so it would be less than Hunter's time. I will help you with this problem, but I will do it with the question "How much longer does it take for Hunter to clean his house?", because the question above doesn't make sense to me.
This is all based on subtraction. You would take the fraction that is more than the other, and use it to subtract the less. You would always want the denominator to be the same, so lets switch it to 2 2/4. Now, you would do 1/4 minus 2/4, which gets you -1/4. You can use the whole hours and fill it in. Since the whole hours is 4/4, you would take 4/4+(-1/4). Simplify and you will get 4/4-1/4. And you would have 3/4.
Now, since the question is asking for how long it take for JEREMY for clean his house, you would say, "it takes -3/4 hours longer for Jeremy to clean his house, since Hunter really takes longer." (Everything in the quote is part of the answer)
Sorry if it is a little confusing.
