Introducing a girl, a boy said "Her father is the only son of my mother". How is the girl related to the boy?

I. p² - 19p + 88 = 0   

II. q² - 48q + 576 = 0

I. 20x² - 93x + 108 = 0

II.72y² - 47y - 144 = 0

I. 2x²– 25x + 33 = 0

II. 3y²+ 40y + 48 = 0

I. 27x⁶- 152x³+ 125 = 0

II. 216y⁶- 91y³+ 8 = 0

I.√(3x-17)+ x=15

II.  y+  135/y=24 

I. 8a² – 22a+ 15 = 0

II. 12b² - 47b + 40=0

In each of these questions, two equations (I) and (II) are given.You have to solve both the equations and give answer   

I. 27x⁶-152x³+125=0

II. 216y⁶ -91y³+8=0

I. x² - 20x + 96 = 0

II. y² - 23y + 22 = 0

I. y² - 7 y – 18 = 0

II. x² + 10 x + 16 = 0