The probability of an event $A$ happening in one trial is $0.4$. The probability that the event $A$ happens at least once in three independent trials is

$A$ fair coin is tossed $100$ times. The probability of getting tails an odd number of times is

An urn contains $25$ balls of which $10$ balls bear a mark $'X'$ and the remaining $15$ bear a mark $'Y'$. $A$ ball is drawn at random from the urn,its mark is noted down and it is replaced. If $6$ balls are drawn in this way,find the probability that the number of balls with $'X'$ mark and $'Y'$ mark will be equal.

$A$ die is thrown $(2n+1)$ times. The probability of getting $1$ or $3$ or $4$ at most $n$ times on it is

Two dice are thrown successively $4$ times and getting a doublet is called a success. The probability of getting at least $1$ success is (in $/1296$)

Two cards are drawn successively with replacement from a well-shuffled pack of $52$ cards. The mean of the number of tens is: