Black and White Balls Puzzle
You have 20 white and 13 black balls in a bag. You pull out 2 balls one after another. If the balls are of same color, then you replace them with a white ball – but if they are of different color, you replace them with a black ball. Once you take out the balls, you do not put them back in the bag – so the balls keep reducing. What would be the color of the last ball remaining in the bag.
Solution: Black
How?
So the solution is very simple,the trick is in the solution itself.Let me give you hint again
"You pull out 2 balls one after another. If the balls are of same color, then you replace them with a white ball – but if they are of different color, you replace them with a black ball."
So, the black balls would always be odd in numbers – either you remove 2 together or remove 1 and add 1 – so they remain odd always. So, the last ball in the bag would be a black ball only.
You have 20 white and 13 black balls in a bag. You pull out 2 balls one after another. If the balls are of same color, then you replace them with a white ball – but if they are of different color, you replace them with a black ball. Once you take out the balls, you do not put them back in the bag – so the balls keep reducing. What would be the color of the last ball remaining in the bag.
Solution: Black
How?
So the solution is very simple,the trick is in the solution itself.Let me give you hint again
"You pull out 2 balls one after another. If the balls are of same color, then you replace them with a white ball – but if they are of different color, you replace them with a black ball."
So, the black balls would always be odd in numbers – either you remove 2 together or remove 1 and add 1 – so they remain odd always. So, the last ball in the bag would be a black ball only.
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