Of the 400 members at a health club, 260 use the weight room and 300 use the pool. If at least 80 of the members do not use either, then the number of members using both the weight room and the pool must be between:  Choose the correct choice from the following options.
A) 40 to 100  B) 240 to 280  C) 230 to 260  D) 240 to 260  E) 200 to 260
W=260   P=300   ALL=400   N(NEITHER)=AT LEAST 80   BOTH=?   W+P-BOTH+N=ALL   260+300-BOTH+80=400   BOTH=240   now pay attention to the fact, that both at most can be 260, since W=260   240 to 260
<result>D</result>
Of the 400 members at a health club, 260 use the weight room and 300 use the pool. If at least 80 of the members do not use either, then the number of members using both the weight room and the pool must be between: