Wanting to know what to formulate V look up with to if factors

eg: if B2=304 and C3=1/2, then v look up = E4

The only problem is B2 can either be 1/2, 1/4, 3/16, or 1/8 and C3 can be
either 304 or 316. I want to have to be positve ( true ) for both if's to
calculate a v look up....

Help!
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Donna