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?
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
#### 75