Question

if 4 positive integers are selected at random from a set of positive integer then what is the probability that the probability that 1,3,7,9 occurs at the units place of the product of the 4 digit so selected

Answer 1

Do we know anything about this set of positive integers that we are selecting from?

Answer 2

No this is the only the question....nothing mentioned anything abt it

Answer 3

if my thought is correct.....you select any 4 numbers having other digits than 1,3,7,9....you wont get these digits in the units place .....so its basically if 1,3,7,9 has to appear in units place then they should be in the units place of the selected digits as well....
so probability is 4/10