###Human: A school bought 20 cartons of pencils at the start of school. Pencils come in cartons of 10 boxes and each box costs $2. The school also bought 10 cartons of markers. A carton has 5 boxes and costs $4. How much did the school spend in all?, ### Assistant: The school bought 20 x 10 = 200 boxes of pencils.
The pencils cost 200 x $2 = $400.
The school bought 10 x 5 = 50 boxes of markers.
The markers cost 50 x $4 = $200.
Thus, the school spent a total of $400 + $200 = $600. 
 So the answer is :  600