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.

Sam found 35 seashells on the beach, he gave Joan 18 of theseashells. How many seashells does he now have?
17.0

Brandy made trail mix for a backpacking trip. She used 0.17 pound of peanuts, 0.17 pound of chocolate chips, and 0.06 pound of raisins. How many pounds of trail mix did Brandy make?
0.4

In one week, Mitch's family drank 0.5 carton of regular milk and 0.1 carton of soy milk. How much milk did they drink in all?

0.6