Solution

Let 

$A_i$ be the event that player $A$ wins $i^{th}$ set.

Given: $P(A_i)=0.6\equiv P(A)~ \forall i \in \{1,~2, ~3,~4,~5\}$ and the winnings in sets are independent.

Answer

p(3)=0.28, p(4)=0.3744, p(5)=0.3456