# shear stress resisted by bolt

In this problem, why did the author use $${(30×10^3)} {/s} = {VQ} /{ I}$$ only? Shouldn't it be $$4(30×10^3) /s = VQ / I$$?

I said so because the board at the centered is connected by 4 bolts , 2 on the left and 2 on the right . The faces on the right also resisted by the same arrangement of nails , right ?

• It would help if you had bothered to define what $Q$, $y'$, and $A'$ are (It's easy enough to guess what $I$ is!) As it stands, the "book answer" is just a "word salad" of random formulae. – alephzero Jan 7 '17 at 22:18