six cards are numbered 1 to 6.with replacement one card is drawn out at random four times. If the products of numbers in the card is 120 , what is the probability that all the four nos are different from each other.
a) 1/3
b) 2/3
c) 4/5
d) 1/2
e) 1/5
a) 1/3
b) 2/3
c) 4/5
d) 1/2
e) 1/5
