shilpaqueen wrote:King Solomon and queen Sheeba have 50 silver coins each. Find the probality that one of them donates n silver coins then the other donates n+- 10 silver coins n<=50)
1/50
1/5
9/25
2/5
3/7
OA is 9/25
King and Queen each have 50 coins.
We need to find the probability that if one of them donates n silver coins then the other donates n+- 10 silver coins.
So, when can be this conditions are possible:
When one donates 1 to 10 coins the other do not have a chance to donate n - 10 coins as n < 11.
When one donates 41 to 50 coins the other do not have a chance to donate n + 10 coins as n > 40.
So out of 50 possible values of n, 20 possible values of n will not let the other distribute n+- 10 coins.
Thus, the probality that one of them donates n silver coins then the other donates
n+10 silver coins = 1 - (20/50)
= 1 - 2/5
= 3/5
Thus, the probality that one of them donates n silver coins then the other donates
n-10 silver coins = 1 - (20/50)
= 1 - 2/5
= 3/5
Thus, the probality that one of them donates n silver coins then the other donates
n+-10 silver coins = (3/5)*(3/5) = 9/25
If the problem is Easy Respect it, if the problem is tough Attack it
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