John is a carpenter. For his friend Ali, he manufactured 4 wooden tables for $20 each and 2 roof frames for $10 each. How much does Ali have to pay John?
For the wooden table, Ali should pay: $20 * 4 = $<<20*4=80>>80
For the roof frames, Ali should pay: $10 * 2 = $<<10*2=20>>20
Combining the wooden table and the roof frames, Ali should pay: $20 + $80 = $<<20+80=100>>100
#### 100