First of all, it is from Alternating Current chapter in Physics.
Given in the question, L=20mH C=120uF R=60ohm t=60s
AC source of 24V/50Hz.
Time period,T =1/50 =20ms
The given is much larger than time peroid,
Hence we can write the average dissipated power
R2=602=3600ohm
X
L=

=2
L =2×3.14×50×20×10-3=6.14ohm
Xc=1/
C =1/2×3.14×50×120×10-6=26.54ohm
Z2=R2+(XL−Xc)2
=3600+(6.14-26.54)2
=3600+416.16
=4016.16ohm2
Average power dissipated,P
av=V
rms×I
rms×

=Vrms×Vrms×R/(Z×Z)
=(Vrms)2×R/Z2
=24×24×60/4016.16
=8.60W