IF Formula Problem

Hi guys!

I do really need your help in solving the next problem. I have this homework that I cannot find any solution to.
I can insert in B3 cell one digit (a), and in B4 (b) another one. And then I have to insert a formula in C3 so that would result a string from D3:O3 with the alternative values b,a,b,a,b,a,b,a etc.

I've attached a print screen of an example. I have this example, but I don't know what formula is involved.

I think it is a IF formula, but I don't know which one. Please, help me! Thanks!

EIE TIC4.png

I don't believe there is one. The exact task sounds like this:
Using the IF function and the + and - operators do the following:
- In B3 and B4 cells you will insert 2 numbers and with the help of a written formula in C3 cell and then copied in D3:O3, you will result in the alternative string of b,a,b,a,b,a etc. values.

Ok.. Thanks anyway!

may be it you desired
write at C3
=INDEX($B$3:$B$4;MOD(COLUMN(A:A)-1;2)+1)
copy to right

Thank you so very much! :D