It takes a new mail carrier 4 hours to deliver the mail on route a. It takes an experienced mail carrier 3 hours to do the same job. How long would it take if they worked together?

Step-by-step explanation:

Given

New mail carrier takes 4 hours for delivery i.e.

New mail carrier completes part of work in 1 hour

Old mail carrier takes 3 hours for delivery  i.e.

mail carrier completes  part of work in 1 hour

If they work together, they complete the work in x hours i.e.

step-by-step explanation:

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value