In a box, there are 20 cards, out of which 10 are lebelled as A and the remaining 10 are labelled as B. Cards are drawn at random, one after the other and with replacement, till a second A−card is obtained. The probability that the second A−card appears before the third B−card is
1116
1316
916
1516
Five digit numbers are formed using the digits 1,2,3,4,5,6 and 8. What is the probability that they have even digits at both the ends
A bag contains 3 white and 7 red balls. If a ball is drawn at random, then what is the probability that the drawn ball is either white or red
A bag contains 8 red and 7 black balls. Two balls are drawn at random. The probability that both the balls are of the same colour is
If Mohan has 3 tickets of a lottery containing 3 prizes and 9 blanks, then his chance of winning prize are
The probability, that in a randomly selected 3−digit number at least two digits are odd, is