Answer:
The minimum number of hours the plumer can work is 1 hour and 15 minutes and the maximum number of hours is 6.
Step-by-step explanation:
This cash flow is a perpetuity. To find the present value of perpetuity, we use the equation of
Pv=C÷r
Pv=39,000÷0.058
Pv=672,413.79
<span>let n+2=u
so, the equation became= [2/u]-[3/u]=5
=> [(2+3)/u]=5
=> 5/u=5
=> u=5/5=1
thus, u=1
we know u=n+2
so, n+2=1
=> n=1-2=-1
so, n=-1</span>
Answer: 
<u>Step-by-step explanation:</u>
