Answer:
Peter and Ann will make 100 copies together in 3.33 hours.
Step-by-step explanation:
Let Ann took the time to make 100 copies of a certain document = x hours
Then per hour work done by Ann =
Time taken by Ralph to compete the work = 2 hours
So per work done by Ralph =
Let the time taken by Peter to complete the work = y hours
Per hour work done by Peter =
It took 75 minutes or hours by Ann, peter and Ralph together to complete the task.
Then per hour work done by all =
And the equation representing per hour work done will be,
Since per hour work done by Ann and Peter is
So time taken to complete the same work by both together will be or 3.33 hours.