a work crew of 7 men takes 10 days to complete one - half of a job . if 8 men are then added to the crew and the men continue to work at the same rate , how many days will it take the enlarged crew to do the rest of the job ?
suppose 1 man can do work in x days . . so 7 men will do in . . 7 / x = 1 / 10 * 1 / 2 as half job is done x = 140 now 8 more are added then 15 / 140 = 1 / 2 * 1 / d for remaining half job d = 4 2 / 3 number of days e
add(10, divide(multiply(7, 10), add(7, 8)))