JEE Main202227 Jun 2022Morning ShiftMathematicsProbabilityActual
Five numbers x 1 , x 2 , x 3 , x 4 , x 5 are randomly selected from the numbers 1 , 2 , 3 , … … , 18 and are arranged in the increasing order x 1 < x 2 < x 1 < x 4 < x 2 . The probability that x 2 = 7 and x 4 = 11 is
Options
- A1 136
- B1 68
- C7 68
- D5 68
Correct answer
B. 1 68
Step-by-step solution
We know x 1 < 7 < x 3 < 11 < x 5 x 1 ∈ 1 , 2 , 3 , 4 , 5 , 6 x 3 ∈ 8 , 9 , 10 x 5 ∈ 12 , 13 , 14 , 15 , 16 , 17 , 18 Required probability P = C 1 6 × C 1 3 × C 1 7 C 5 18 = 1 68