The electron in hydrogen atom makes a transition from n=n1 to n=n2 state. The time period of the electron in the initial state is eight times that in the final state. The possible values are
n1=4,n2=2
T=2πrv and r∝n2,v∝1/n⇒T∝n3T1T2=(n1n2)38=(n1n2)3 or n1n2=2