Explanation:
so, he will not wear any pants ? socks ? not to mention underwear ?
anyway, we have to deduct the $35 for the shoes, as he is seemingly buying them in any case.
so, we are left with 100 - 35 = $65 for shirts.
as one shirt costs $15, we need to see how often 15 fits into 65, as that is the answer how many shirts he can buy for this money.
65 / 15 = 4.333333333...
since he cannot buy a part shirt, we can only rely on the integer part of the calculation.
so, he can buy 4 shirts and will have $5 left.