Okay. So, in all, he spends $335 on gas, and two new tires. And it's mentioned that the gas costs $60. So we would have to deduct $60 from $335 to find how much the tires costed in all, before we find out how much each tire costs.
335 - 60 = 275.
And so that means that two tires together costed $275 in all. Now, the question itself is asking how much each tire costed. So we would have to split 275 in two to find how much each tire costed (and because there are two tires, therefore breaking 275 in half.) And that would mean that we would have to divide 275 by two.
274 ÷ 2 = 137.5
And that number ^ in money form would become $137.50. And so each tire costs $137.50. Your answer is D.