Each coefficient in the equation `a x^2+b x+c=0` is determined by throwing an ordinary six faced die. Find the probability that the equation will have real roots.

Explanation

We know that roots are equal if equal

`=>b^2−4ac=0`

If `b=1` then

`1/4=ac.` No integral values of a and c.


If `b=2` then

`=>4-4ac=0`

`=>1=ac`

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