The solution for velocity, concentration and temperature boundary layers will be same if
(a) Prandtl number = Schmidt number= Lewis number
(b) Prandtl number = 2 Schmidt number= Lewis number
(c) Prandtl number = Schmidt number= 2 Lewis number
(d) 2 Prandtl number = Schmidt number= Lewis number
This question was addressed to me at a job interview.
The query is from Convective Mass Transfer in chapter Modes and Diffusion of Mass Transfer