Question

A motor boat goes 10 km upstream and returns back to the starting point in 55 minutes. If the speed of the motor boat in still water is 22 km per hour,find the speed of current.

Answer 1

Answer:

Let speed of motor boat = x

downstream speed = x + 2

upstream speed = x - 2

so,

10/(x + 2)+10/(x - 2) = 55/60

55x^2-1200x-220

x=22

Step-by-step explanation:

Answer 2

Answer:

The speed of current is 22 km/hr .

Step-by-step explanation:

Let The speed of motor boat in still water be x km/h

We are given that the speed of the motor boat in still water is 2 km/hr

Downstream speed = (x+2) km/hr

Upstream speed= (x-2) km/hr

A motor boat goes 10 km upstream and returns back to the starting point in 55 minutes.

$Time = \frac{Distance}{Speed}$

$\frac{10}{x-2}+\frac{10}{x+2}=\frac{55}{60}$

[tex]11x^2-240x-44 = 0 [/tex]

[tex](x-22)(11x+2) = 0 [/tex]

x=22, -11/2

Hence the speed of current is 22 km/hr .