With the given condition given the set of a = ( 1, 2, 3, 4, 5, 6, 7, 8)
For the set of b = ( 6, 7, 8, 9, 10, 11, 12)
For the roots of the equation to be real and distinct :the condition is that for a quadratic equation of the form
$$ax^2+bx+c\ =\ 0\ ,\ b^2-4ac>0$$.
For b = 6 the equation is of the form 36 - 12a >0. a will take the values of (1,2)
For b = 7 the equation is of the form 49 - 12a >0. a will take the values of (1,2, 3, 4)
For b = 8 the equation is of the form 64 - 12a >0. a will take the values of (1,2, 3, 4, 5)
For b = 9 the equation is of the form 81 - 12a >0. a will take the values of (1,2, 3, 4, 5, 6,)
For b = 10 the equation is of the form 100 - 12a >0. a will take the values of (1,2, 3, 4, 5, 6, 7, 8)
For b = 11 the equation is of the form 100 - 12a >0. a will take the values of (1,2, 3, 4, 5, 6, 7, 8)
The minima will be present at x = -b/2a which should be greater than -1
for b = 6 for this to happen the the value of 2a should be greater than 6 and hence a >3 and no cases are possible.
for b = 7 for this to happen the the value of 2a should be greater than 6 and hence a >3.5 and hence a = 4, (1 case)
for b = 8 for this to happen the the value of 2a should be greater than 6 and hence a >4 and hence a = 5, (1 case)
for b = 9 for this to happen the the value of 2a should be greater than 6 and hence a >4.5 and hence a = 5, 6 ( 2 cases)
for b = 10 for this to happen the the value of 2a should be greater than 6 and hence a > 5 and hence a = 6, 7, 8 ( 3 cases)
for b = 11 for this to happen the the value of 2a should be greater than 6 and hence a > 5.5 and hence a = 6, 7, 8 (3 cases)
Total of = (1+1+2+3+3) = 10 cases