HELP!! Edexcel A level Maths Statistics

I am stuck to do with question b). I don’t know how to start.. I don’t understand the question tbh. I suppose there will be two simultaneous equations in terms of m and n? Any help will be appreciated..

There is only one way (eacb) to get the probabilities of 1/4 and 1/6. That then gives the r and g in each equation and hence you have two simultaneous equations to solve as usual.

Its hardly giving the game away to say part a) helps.

Do you mean I use the answers from question a)? So .. simultaneous equations will be

2m + n = 20
3m + 4n = 50