$55=5\times 11$  $100=2\times 2\times 5\times 5$  Because $B$ is the factor both number contains, $B=5$  Thus, $A=11$, $C=20$. 
There are three whole numbers $A$, $B$ and $C$. $A\times B=55$, $B\times C=100$. $A+B+C=$~\uline{~~~~~~~~~~}~. 

(1) $$30$$ 
(2) $$32$$ 
(3) $$34$$ 
(4) $$36$$ 