If 10 men can construct a building in 40 days how long will it take 1 man to do this work

Work problems are solved using the formula Work equals Men multiplied by Days. If 10 men can finish in 40 days then total work is 10 multiplied by 40 which is 400 man days. Now for one man to do the same work alone it will take 400 days. This is because one man completes only one unit of work per day while 10 men together complete ten units. Such problems show the inverse relationship between number of workers and time. These calculations are practical in construction projects business planning and exams that test arithmetic reasoning.