Three-ring notebooks are made in 2 steps. Machine A makes 180 covers per hour. Later, machine B attaches.....?

Question

cont'd..
attaches the 3-ring paper holder and completes 150 notebooks per hour. How many hours should Machine A run in order to produce the right number of covers for machine B to finish in exactly 8 hours of its operation?



(this problem confuses me..could someone help and show me how they figured out their answer PLEASE. Thanks!!!

Answer 1

eight hours of operation of machine B finishing 150 binders per hour would need 8*150=1200 items to complete.
For machine A to create 1200 items to pass to machine B would take the number required divided by the number per hour machine A is able to create. 1200/180=400/60=6 remainder 40
That equates to 6 hours 40 Minutes or 6 2/3 hours.

Answer 2

Machine B does 150 notebooks per hour.
In 8 hours, machine B would do 150*8 = 1200 notebooks.

Machine A makes 180 covers an hour.
In order to make 1200 covers, machine A must work 1200/180 = 20/3 = 6 2/3 hours (or six hours and 40 minutes)

Answer 3

Set up a system of eqns:

180x = A
150*8 = B

A=B
180x = 150*8
180x = 1200
x=1200/180 = 20/3 hrs