Coefficients of quadratic equation \(a x^{2}+b x+c=0\) are chosen by tossing three fair coins where 'head' means one and 'tail' means two. Then the probability that roots of the equation are imaginary is
Step-by-step Solution:
Total number of cases is 8. \[\] \(a, b, c\) can take values 1 and 2 only. The roots are real when \(b=2, a\) and \(c\) are 1,1 . \[\] Required probability \(=1-\frac{1}{8}=\frac{7}{8}\). \[\] Choice (A)