To be sure, to pick atleast 2 marbles of a same color we need to grab at least 4 marbles, since the worst case is that three of them are different, the fourth marble has to be a repetition of one of three colors.

This question is often asked in companies where new reps will be selling cardiovascular products; however, occasionally seen it in other companies where new reps are selling in different therapeutic areas.  The major difference between a stroke and heart attack is the part of the body that is affected: stroke affects the brain, a heart attack affects the heart.

A stroke or "brain attack" occurs when a blood clot or some other small particle blocks the blood vessel supplying that part of the brain, or when a vessel weakens, causing it to leak and bleed into the surrounding tissue.

A heart attack also occurs when there is a blockage in a blood vessel, only in this case it is in the arteries that supply the heart muscle with oxygen and blood. The blockage in the heart vessels may be due to blood clots or small particles of plaque.