JEE Main202228 Jun 2022Evening ShiftMathematicsFunctionsActual
The probability that a randomly chosen one-one function from the set a , b , c , d to the set 1 , 2 , 3 , 4 , 5 satisfied f a + 2 f b - f c = f d is
Options
- A1 24
- B1 40
- C1 30
- D1 20
Correct answer
D. 1 20
Step-by-step solution
Total cases will be 5 C 4 × 4 ! Now favourable cases for 2 f b = f c + f d - f a will be, Case (I) if f b = 1 then f c ,   f d ,   f a can take the value 3 , 4 , 5 & 4 , 3 , 5 respectively Case (II) if f b = 2 then f c ,   f d ,   f a can take value 3 , 5 , 4   &   5 , 3 , 4 respectively Case (III) if f b = 3 then f c ,   f d ,   f a can take value 2 , 5 , 1   &   5 , 2 , 1 respectively So total favourable case will be 6 So probability = favourable