A school choir needs robes for each of its 30 singers. Currently, the school has only 12 robes so they decided to buy the rest. If each robe costs $2, how much will the school spend?
The school needs to buy 30 - 12 = <<30-12=18>>18 robes.
So the school will spend 18 x $2 = $<<18*2=36>>36.
#### 36