In a week, Mr. Alvarez uses $36/$3 = <<36/3=12>>12 gallons a week.

So in two weeks, he uses 12 x 2 = <<12*2=24>>24 gallons.

# Answer

24
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Mr. Alvarez spends $36 on diesel fuel each week. If the cost of diesel fuel is $3 per gallon, how many gallons of diesel fuel does Mr. Alvarez use in two weeks?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
24
Mr. Alvarez spends $36 on diesel fuel each week. If the cost of diesel fuel is $3 per gallon, how many gallons of diesel fuel does Mr. Alvarez use in two weeks?
train