How many sets contains 6 or its multiple given the following conditions? 
MyApproach
I created 
@Edit
S1={1,2,3,4,5} ...B)
S2={2,3,4,5,6}
S3={3,4,5,6,7}
S4={4,5,6,7,8}
S5={5,6,7,8,9}
S6={6,7,8,9,10}
S7={7,8,9,10,11}  ....A)
S8={8,9,10,11,12}
From this information I analyzed that these $8$ sets have $6$ sets that have 6 or its multiple.
Thus $80$ sets will have $60$ elements which contain $6$ or its multiple.
Is my Ans right?Please correct me if I am wrong?

You can see that for x between 1 and 6 there are 5 sets which contains 6 or its multiple. and that will be the same for every x between y and y+5.
There are 80 sets so the answer should be  $\lceil 80-(\frac{80}{6}+1) \rceil$ = 66
