A doctor attends five patients in 45 minutes. How many hours he has to work if he has to attend 50 patients?
6 hours
6.5 hours
7 hours
7.5 hours
Let's first calculate the time the doctor takes to attend one patient.
The doctor attends 5 patients in 45 minutes, so for 1 patient, the time taken is:
\(\frac{45}{5}=9\) mintues per paitent.
Now, to attend 50 patients, the total time required is:
\(50\times9=450\) minutes
Convert 450 minutes into hours:
\(\frac{450}{60}=7.5\) hours
Thus, the doctor needs to work 7.5 hours to attend 50 patients.
The correct option is (D):7.5 hours