math question

Question

It takes 7 machines 7 minutes to fabricate 7 pieces of aluminum. How long does it take 140 machines to fabricate 140 pieces of aluminum?

Answer 1

each machine produces 1/7 of a piece per min , after 7 minutes each machine produces 1 piece

 

And with 7 machines , they would produce 7 pieces

 

Therefore a machine's rate is 1/7 of a piece per minute

 

Therefore, 140 machines can produce 140/7 peices per minute

 

140 pieces divided by (140/7) is still 7 minutes