Marbles question (not probability)

Neenahboy

New member
Joined
Apr 27, 2007
Messages
1
A box contains red marbles and blue marbles. If Bob selects a handful at random (without replacement), she needs at least 5 marbles to be sure at least one of them is red and at least 10 to be sure both colors appear among the marbles selected. How many marbles are in the box?
 
Top