I have 200 candies in an hourglass dispenser. There are 40 each of red, white, blue, yellow and green. Each time I turn the hourglass over the candies get thoroughly mixed and 20 candies are poured into a cup. I like the blue candies best.

When I want candy, I turn over the dispenser and sort through the candies in the cup. I leave all of the blue ones in the cup and put the rest back. Then I turn over the hourglass a second time. The dispenser fills the cup so that I get exactly 20 candies, which I eat. I continue this way until the dispenser is empty.

How many blue candies will be in the final cupful?

Note:The dispenser dispense just the right amount so that to total will still be 20; so if 4 blues remain, it will dispense 16.

(In reply to re(2): simulation by Charlie)

My interpretation is 20 candies go into an empty cup.  If the 20 includes 'n' blues, the 'n' blues stay in the cup and the (20-n) non-blues go back into the mixer which gets remixed.  Then 20-n mixed candies enter the cup.  Now the cup has 20:  some blues from Round 1, part A; and perhaps some blues from Round 1, part B; and some non-blues.  The cup is then emptied / eaten.  

Posted by Larry on 2023-12-12 20:17:04