Question

Four numbers are chosen at random (without replacement) from the set {1, 2, 3, ....., 20}.
Statement-1: The probability that the chosen numbers when arranged in some order will form an AP is 1/85.

Statement-2: If the four chosen numbers from an AP, then the set of all possible values of common
difference is {±1, ±2, ±3, ±4, ±5}.

Answer 1

Four numbers are chosen at random (without replacement) from the set {1, 2, 3, ....., 20}.
Statement-1: The probability that the chosen numbers when arranged in some order will form an AP
is 1/85

Statement-2: If the four chosen numbers from an AP, then the set of all possible values of common
difference is {±1, ±2, ±3, ±4, ±5}.


(1) Statement-1 is true, Statement-2 is true; Statement-2 is not the correct explanation for Statement-1
(2) Statement-1 is true, Statement-2 is false
(3) Statement-1 is false, Statement-2 is true
(4) Statement-1 is true, Statement-2 is true; Statement-2 is the correct explanation for Statement-1.

Answer 2

3

Answer 3

No, not correct. :(