If the wavelength of line B is 142.5 nm, calculate the wavelength of line A.

Question

Line A is the transition of n=6 to n=3
Line B is the transition of n=5 to n=3

Answer 1

lambdaA/lambdaB=(1/36-1/9)/(1/25-1/9)

check my thinking.

Answer 2

i don't get it