Thread: If statements

I have three cells
A1 will be 25% or 0
A2 will be 25% or 0
A3 will be 50% or 0
C1 the sum of A1,A2,A3
I need to create a formula that calculates the sum of these percentages. Easy enough, BUT if A1 or A2 were to be 0 I need a 50% penalty to be applied.
So if
a1=0
a2=25%
a3=50%
C1=25%
But the penalty should not be applied more than once even if A1 & A2 are 0. If someone could help me on this that would be awesome. I am fairly fimilar with IF statements but this seems a little more complex than I can seem to come up with.

results:
when A1:A3 should have been 100% it turned up 25%
I am trying to track percent of bonus earned. There are 3 catagories to be met call them cat1 cat2 cat3 (discretionary). If cat1 or cat2 are missed then cat3 is automatically missed. cat1=25% cat2=25% cat3=50% This is what i am trying to represent in the formula above. Hopefully this helps

thank you that did not solve my problem but i figured out what would what i did was made
A3=IF(G16="True",IF(COUNTIF(A1:A2,0),0,0.5))
Before it was =IF(G16="True","50%","0")
then for C1 =A1+A2+A3
Thanks for your help. I did not know about count if before.