Question 190101
An easy way to work with the mixed number 6 4/15 is
to convert the fraction to one with {{{60}}} in the 
denominator. 
A good rule is that you can always multiply a fraction by
{{{1}}} without changing it. All these fractions equal {{{1}}}:
{{{5/5}}},{{{11/11}}}.{{{659/659}}}, etc.
What you should use is {{{4/4}}}
{{{(4/4)*(4/15) = 16/60}}}
In this problem, {{{16/60}}} is a fractional part of an hour.
In order to get minutes, note that {{{1/60}}} of an hour is
{{{1}}} minute, so {{{16/60}}} of an hour is {{{16}}} minutes
Now I can say 6 4/15 hours = 6 hours and 16 minutes
{{{1}}} hour has {{{60}}} minutes, so {{{6}}} hours has
{{{6*60 = 360}}} minutes
So far I have 6 4/15 hours = {{{360 + 16}}} minutes
{{{360 + 16 = 376}}} minutes
So, 5 employees each work {{{376}}} minutes per day
Altogether, they work {{{5*376 = 1880}}} minutes
The problem wants the answer in hours, so
{{{1880/60}}} = 31 1/3 hours
1/3 hour is 20 minutes because {{{3*20 = 60}}} minutes
The 5 employees work 31 hours and 20 minutes