Thirty men can do a work in 24 days. In how many days can 20 men can do the work, given that the time spent per day is increased by one-third of the previous time?	Choose the correct choice from the following
A) 25 days  B) 26 days  C) 20 days  D) 27 days  E) 21 days
D   27 days   Let the number of hours working per day initially be x. we have M1 27 days1 H1= M2 27 days2 H2   30 * 24 * x = 20 * d2 * (4x)/3 =&gt; d2 = (30 * 24 * 3)/(24 * 4) = 27 days.
<result>D</result>
Thirty men can do a work in 24 days. In how many days can 20 men can do the work, given that the time spent per day is increased by one-third of the previous time?