Let x represent the number of days required for the faster individual (assumed to be A) to complete the work independently.
When A operates at 60% capacity and B operates at 150% capacity, their combined work rate is equivalent to \( \frac{3}{5} + \frac{3}{2} \) of the standard capacity.
The equation \( (\frac{3}{5}+\frac{3}{2}).\frac{1}{x}=\frac{1}{20} \) is established based on the premise that A and B, working collaboratively, can complete the task in 20 days.
The solution to this equation yields x=36.
Consequently, the faster individual (A) will complete the work independently in 36 days.