MHT CET202619 April 2026Morning ShiftMathematicsQuadratic EquationActual
Let a be an integer selected at random from the set 0, 1, 2, 3, , 9 . The probability that the equation ax^2 - ax + 1 = 0 has real roots is ...
Options
- A3 5
- B1 2
- C2 5
- D5 9
Correct answer
A. 3 5
Step-by-step solution
The total number of possible values for a from the set 0, 1, 2, 3, , 9 is 10 . For the equation ax^2 - ax + 1 = 0 to have real roots, we consider two cases: If a = 0 , the equation becomes 1 = 0 , which has no roots. If a 0 , the equation is a quadratic equation. For it to have real roots, its discriminant must be non-negative. D = (-a)^2 - 4(a)(1) 0 a^2 - 4a 0 a(a - 4) 0 Since a 1, 2, 3, , 9 , the condition a(a - 4) 0 is satisfied when a 4 . The favorable values of a are 4, 5, 6, 7, 8, 9 . The number of favorable