4 is the answer.
Numbers have first 3 digits in increasing order 2468 2486 2684 4682
Possible event of formation of 4 digits numbers by rearranging the digits 2, 4, 6, 8 is... 4! = 4×3×2×1 = 24 But, the numbers having first 3 digits in increasing order are, 2468, 2684, 4682, 2486 Therefore, probability will be... 4÷24 = 1/6
A four digit positive number having all non-zero distinct digits is such that the product of all the digits is least. If the difference of hundreds digit and tens digit is 1. How many possibilities are there of such number?
A non negative number having all distinct digits is such that the product of all digits of the number is 504. What will be the probability that the number has sum of all its digits 25 ?
Two digits are selected at random from digits 1 through 9. If sum is even, find the probability that both numbers are odd?
A man throws three dices simultaneously on the floor. What is the probability of getting three numbers whose product is even?