Second Attempt Ki Teyyari Kese Kare?

One of 10 keys open the door. If we try the keys one after another, then find the following: (i) The probability that the door is opened on the first attempt. (ii) The probability that the door is opened on the second attempt. (iii) The probability that the door is opened on the 10th attempt.

One of the ten available keys opens the door. If we try the keys one after another, then find the following (i) the probability that the door is opened in the first attemt. (ii) the probability tht the door is opened in the second attempt. (iii) the probability that the door is opened in the third attempt. (iv) the probability that the door is opened in the tenth attempt.

A programmer noted the results of attempting to run 20 programs. The results showed that 2 programs ran correctly in the first attempt, 7 ran correctly in the second attempt, 5 ran correctly in the third attempt, 4 ran correctly in the fourth attempt and 2 ran correctly in the fifth attempt. What is the probability that his next programme will run correctly on the third run ?

Aqueous solution of KI dissolves I_(2) to form KI_(3) . Which of the following statements is (are) true ?