speed of andrew is 3.3 kph,
distance travel by andrew in 20 min = km
let at time t they will met , since speed of janes is constant so time take of going and coming will be same.
And total time to travel= 40 min so , time for going and coming , t = 20 min = hr
so, Let us take speed of janes be v
distance cover by janes in 20 min = distance cover by andrew in 40 min
this is the constant speed of janes