13

Part of 2014-2015 SDML (Middle School)

Problems(1)

Subset of {100} with no member thrice another

Source: 2014-2015 SDML Middle School 1a Problem 13

S

be a subset of the integers

1,2,\ldots,100

that has the property that none of its members is

3

times another. What is the largest number of members

S

\text{(A) }67\qquad\text{(B) }71\qquad\text{(C) }72\qquad\text{(D) }76\qquad\text{(E) }77