You are provided with an arithmetic question. Your task is to compute the solution using the given arithmetic operations. The only arithmetic operators needed to answer the questions are'+'(addition) and'-'(subtraction). The answer should be correct to one decimal place.

[Q]: Keith spent $136.06 on speakers, $139.38 on a CD player, and $112.46 on new tires. He wanted 3 CD's for $6.16, but did n't buythem. In total, how much did he spend?
[A]: 387.9


[Q]: Tim found 679 seashells and 110 starfish on the beach. He gave 172of the seashells to Sara. How many seashells does Tim now have?
[A]: 507.0


[Q]: Oscar's bus ride to school is 0.75 mile and Charlie's bus ride is 0.25mile. How much longer is Oscar's bus ride than Charlie's?
[A]:
0.5