Directions (next five questions) : In these questions, two equations numbered I and II are given. You have to solve both the equations and mark the appropriate option.
I. 5x2+8x+3=0
II. 3y2+7y+4=0
⇒ 5x2+5x+3x+3=0
⇒ 5x(x+1)+3(x+1)=0
⇒ (x+1)(5x+3)=0
⇒ x=-1,-3/5
⇒ 3y2+4y+3y+4=0
⇒ y(3y+4)+1(3y+4)=0
⇒ (3y+4)(y+1)=0
⇒ y=4/3,-1
∴ x ≥ y
I. 3x2-13x+12=0
II. 3y2-13y+14=0
I. 2x2+15x+27=0
II. 2y2+7y+6=0
I. 2x2-9x+10=0
II. 2y2-13y+20=0
I. x2=144;
II. y2-24y+144=0
The time taken by a boat to travel a distance downstream is half the time taken by it to travel the same distance upstream. What is the speed of the boat downstream if it travels 7.5 km upstream in 1 hour 30 min ? (in km/h)