Radiology Question - PLEASE HELP

Dec 2019
1
0
London
Can anyone advise me on the calculation for working out an effective dose for and external source as oppose to equivalent dose using the following information:

Absorbed dose is 20mGy of alpha particles and 10mGy of gamma rays assuming and RBE of 1.7

Radiation weighting for alpha particles is 20 and for gamma particle is 1

Would the answer be in Sv?