Answer:
Step-by-step explanation: Machine A makes 144 parts in 6 hours. Machine B makes 468 parts in 9 hours. If we divide 144 from 6 we will get 24 parts per hour. 468 divided by 9 would be 52. Now 52 times 12 is 624. 24 times 12 is 288 So if we subtracted 624-288=336.
So Machine B Makes 336 more parts after 12 hours. Hoped this helped!