He makes $300 selling the books because 200 x 1.5 = <<200*1.5=300>>300

He spends $225 on records because 75 x 3 = <<75*3=225>>225

He has $75 left because 300 - 225 = <<300-225=75>>75

# Answer

75
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Thomas owns 200 books. He decides to sell them and use the money to buy records. Each book sells for $1.5. A record costs $3. If he buys 75 records, how much money does he have left over?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
75
Thomas owns 200 books. He decides to sell them and use the money to buy records. Each book sells for $1.5. A record costs $3. If he buys 75 records, how much money does he have left over?
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