Question 752192
If 6 men can do a work in 20 days, and one man can do the work of two boys,
 then in how many days can 10 men and 5 boys do the same work.
:
Find how many man-days required to complete the job
6 * 20 = 120 man-days
:
1 man-day = 2 boy-days
:
"how many days can 10 men and 5 boys do the same work."
5 boy-days = 2.5 man-days
let d = number of days required for this scenario
10d + 2.5d = 120 
12.5d = 120
d = 120/12.5
d = 9.6 days for 10 men and two boys to complete the job