How Do Radiation Weighting Factors Affect Equivalent Dose Calculations?

[CheesyPeeps]

A worker in a nuclear power station is exposed to 3∙0 mGy of gamma radiation and 0∙50 mGy of fast neutrons. The radiation weighting factor for gamma radiation is 1 and for fast neutrons is 10. The total equivalent dose, in mSv, received by the worker is
A 3·50
B 8·00
C 30·5
D 35·0
E 38·5.

The answer I got (using H=DW_R) was C, 30.5 mSv, but the answer sheet said that the correct answer was B, 8.00 mSv.
I would be most grateful if you could please suggest where I went wrong?
Thank you for your help!

(This question is from the SQA National 5 Physics Specimen Paper)

Update: I asked a friend about it and realized my mistake. I converted mSv into Sv when I didn't need to, which then affected my answer.

 

[haruspex]

I asked a friend about it and realized my mistake. I converted mSv into Sv

That does not explain your wrong answer. It is explained if you crossed over the weighting factors.