In 7 weeks 5*7 = <<35=35>>35 goldfish die.

In 7 weeks, Martin purchases 3*7 = <<3*7=21>>21 goldfish.

In 7 weeks, Martin will have 18-35+21 = <<18-35+21=4>>4 goldfish.

# Answer

4
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Martin has 18 goldfish. Each week 5 goldfish die. Martin purchases 3 new goldfish every week. How many goldfish will Martin have in 7 weeks?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
4
Martin has 18 goldfish. Each week 5 goldfish die. Martin purchases 3 new goldfish every week. How many goldfish will Martin have in 7 weeks?
train