A five-digit number is formed by using digits 1, 2, 3, 4 and 5 without repetition. What is the probability that the number is divisible by 4?
None of these
Solution:Option(A) is correct
A number divisible by 4 formed using the digits 1, 2, 3, 4 and 5 has to have the last two digits 12 or 24 or 32 or 52.
In each of these cases, the five digits number can be formed using the remaining 3 digits in $3! = 6$ ways.
A number divisible by 4 can be formed in $6×4 = 24$ ways.
Total number that can be formed using the digits 1, 2, 3, 4 and 5 without repetition
$= 5! = 120$
Error(s) Found !!!
S Malik (Oct 11'16 at 18:05)
any one please explain it with another method...
Fill out the name first.
Posting as #name, Edit Details
To write Maths use $ or $$ delimiters. (TeX)Ex: $ax^2+bx+c=0$.
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