Annie got a robotics kit for her birthday. She is building a laundry robot that can take out her clothes from the dryer and fold them. She has some of it complete, but the robot still needs 3
arms and 5 wheels. Annie has saved up $78, which is enough to buy the parts she needs.
She looks at a robotics catalog to see how much it will cost.
Cost
Arms
$15
Wheels
$6
How much money is left over after Annie buys the parts?