If function in calculation

Hi guys

I need to use the if function or maybe there is an easier way, the information I have is like below

A1. B1. C1. D1. E1. F1. G1
50. Yes. 100. 60. Yes

What I need to put in is if B1 says yes then add A1 and if D1 says yes then add C1 or if it blank add 0
And so on, in G1 I need the total for A1, C1, E1, it does go on a lot more but if I can get the correct function for the above it would be fab.

Any suggestions it's doing my head in
Thanks