Blue and red marble riddle is the hardest math’s puzzle. Here is the correct answer with step-by-step explanation to this puzzle called Blue and red marble. The puzzle is based on probability so try to answer it and if you liked it do share it with you friends.
Blue and Red Marble Riddle Question
Puzzle:
You have two jars, 50 red marbles and 50 blue marbles. You need to place all the marbles into the jars such that when you blindly pick one marble out of one jar, you maximize the chances that it will be red. When picking, you’ll first randomly pick a jar, and then randomly pick a marble out of that jar. You can arrange the marbles however you like, but each marble must be in a jar.
Blue and Red Marble Riddle Answer
The simple way to maximize our chance will be:
Probability of picking a random jar will give you 0.5 for each jar 1 and 2.
If you place only red marbles in jar 1 and blue in jar 2 then the probability will be 0.5 × 1 = 0.5 (same as jar 2)
1 because the probability of drawing a red marble from jar 1 will be equal to 1.
Even if you put only one red marble in the jar 1 the probability of drawing a red marble remains the same that is 1. The chances will be 0.5 × 1= 0.5
To maximus the probability in case you randomly select the 2nd jar, we can increase the probability of second jar because the 1st jar remains the same with the one marble inside.
So, the answer to the Blue and red marble riddle will be: we will place the all 49 remaining red marbles with the blue marbles in the jar 2 to max the probability in case your 2nd jar is selected.
Now the probability will be equal to:
0.5 × (49/99) = 0.2474
Total probability will be equal to:
0.5 + 0.247 = 0.747