The given following series I and II are different logical patterns solve the following questions

Series I: 2K, 49, 75, 140, 264, 481

Series II: 20, 40, 3L, 600, 4200,46200

i) x2 + ax - 800 = 0, K is one of the roots of the equation

ii) y2 + by - 3200 = 0, L is one of the roots of equation 

Find (a + b)