You are given a box of 100 silver dollars, all facing "heads" up. You are instructed to shake the box 3 times; after each shake, you will remove all the dollars that are "heads up" before shaking again. You may keep all the dollars that are still tails up following the third shake. How many dollars will you most likely get to keep?

A. Less than 10 percent
B. 25 percent
C. 50 percent
D. More than 75 percent

Question

You are given a box of 100 silver dollars, all facing "heads" up. You are instructed to shake the box 3 times; after each shake, you will remove all the dollars that are "heads up" before shaking again. You may keep all the dollars that are still tails up following the third shake. How many dollars will you most likely get to keep?

A. Less than 10 percent
B. 25 percent 
C. 50 percent
D. More than 75 percent

redheadangel · Answer

100 * (1/2)^3 = 12.5 so 12 is the best answer. 

Each time you shake the box and remove the coins you expect to remove half of the coins remaining.

anonymous · Answer

So between A and B?

redheadangel · Answer

Yea... I'm not sure what you should put then...

anonymous · Answer

Me too ;; I'm gonna take my chance with B I guess...

redheadangel · Answer

Sounds good :)

anonymous · Answer

Yeah I asked someone else the question and I'll tell you what he says c: