Peter bought 4 new notebooks for school. 2 of them are green, one is black and the other one is pink. The total cost was $45. If the black notebook cost $15, and the pink one cost $10, how much did the green notebooks cost each?
The black and pink notebook cost a total of $15 + $10 = $<T>add(15, 10)=25
The green notebooks cost a total of $45 - $25 = $<T>subtract(45, 25)=20
Each green notebook cost $20 / 2 = $<T>divide(20, 2)=10.0
