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Question : 22
Total: 29
A die is thrown again and again until three sixes are obtained. Find the probability of obtaining the third six in the sixth throw of the die.
Solution:
p = probability of success =
Third six comes at the 6th throw so the remaining two sixes can appear in any of the previous 5 throws.
Probability of obtaining 2 sixes in 5 throws
=
C 2 ×
×
×
6th throw definitely gives six with probability =
Required Probability
=
=
Third six comes at the 6th throw so the remaining two sixes can appear in any of the previous 5 throws.
Probability of obtaining 2 sixes in 5 throws
=
6th throw definitely gives six with probability =
Required Probability
=
=
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