or
or
Total unit of work 20×15 = 300 unit
1st 10 day work 20×10 = 200 unit
Remaining unit of work 300 - 200 = 100
Since m man leave after 10 day
ATQ
10×(20 - m) = 100
= > 20 - m = 10
= > m = 10
Ans. 10 man
[N.B. man×day = unit ]
