TIFR PROBABILITY GS 2021 (INDIA)
Probability
Level
3
What is the expected number of tosses needed from a fair coin to get at least 1 head and 1 tail?
The answer is 3.
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1 solution
The first trial is either head or tail.
A fair coin, E ( H ) = E ( T ) = 2
So, the answer is 1 + 2 = 3 .
There is another problem to see all faces at least once of a dice