Seeing in the given circuit C1​ and C2​ are connected in parallel. Hence, their equivalent capacitance Ceq​=C1​+C2​=5+10 =15μF
As Ceq​ and C3​ are connected in series, Hence, resultant capacitance between P and Q is given by CPQ​1​=Ceq​1​+C3​1​ =151​+41​=6019​ CPQ​=1960​=3.2μF