Consider a laundry service that has 3 steps to its process.
Step 1 is Washing, Step 2 is Drying, Step 3 is Ironing & Step 4 is Packaging.
Step 1 Washing is a batch operation, with a batch size of 50 pieces of clothing, variable time of 15 seconds per piece and a fixed time of 20 minutes. There is one washing machine.
Step 2 Drying is also a batch operation, with a batch size of 40 pieces of clothing, variable time of 20 seconds per piece, and a fixed time of 60 minutes. There is one drying machine.
Step 3 is a manual operation where a team of 2 workers iron the clothes; each worker takes on average 3 minutes to iron a piece of clothing.
Step 4 is again a manual operation, where only one worker packages the clothes in an average of 2 minutes per piece; only 50% of the clothes need packaging.
Answer the next several questions based on the data above.
The capacity at washing in pieces of clothing per hour is (pick the closest integer):
a 62 per hour
b 72 per hour
c 92 per hour
d 102 per hour