Correct option is C
Given:
Ram can complete the task in 20 days.
Shyam can complete the task in 30 days.
Formula Used:
Combined Work Rate=Time taken by Ram1+Time taken by Shyam1Total Time=Combined Work Rate1
Solution:
Combined Work Rate = 201+301=603+602=605=121
Total Time=1211=12days
Alternate Solution:
Total Work = LCM of 20 and 30 = 60 unit
Efficiency of Ram = 2060= 3 unit per day
Efficiency of Shyam = 3060 = 2 unit per day
Total Time=Combined EfficiencyTotal Work=2+360=12days