Ramesh and Mahesh solve a quadratic equation. Ramesh reads its constant term wrongly and finds its roots as $8$ and $2$ where as Mahesh reads the coefficient of $x$ wrongly and finds its roots as $-11$ and $1$. The correct roots of the equation are

Ramesh read the constant term wrong, so the coefficient of x (sum of roots) is correct. Sum = 8 + 2 = 10, so the equation is x^2 - 10x + c = 0. Mahesh read the coefficient of x wrong, so the constant term (product of roots) is correct. Product = -11 * 1 = -11. The equation is x^2 - 10x - 11 = 0. Roots are (x-11)(x+1) = 0, so 11 and -1.