Question

Board Q....pls solve i need it

Answer 1

heya mate ❤
it's nice to meet uh
here's ua answer :

SOLUTION
Given :
The speed of the motor bike instill water is 18 kmph,
It takes 1 hour to travel upstream & return to same spot,.

From this information we can say that,

⇒ The speed of motor boat (boat's engine) = 18 kmph ,

⇒ It traveled 24 km upstream & 24km downstream in 1 hour,.

_____________________________________________________________

To Find :

The speed of stream .

_____________________________________________________________

We know that,

time = distancespeed\frac{distance}{speed}
speed
distance
​


So,

Let the speed of stream be x,

Then,

we can say that,

⇒ 2418−x−2418+x=1\frac{24}{18 - x} - \frac{24}{18 + x} = 1
18−x
24
​
−
18+x
24
​
=1 .....(i) (All the units are in hour km per hour,etc,.)

⇒ 24(18+x)−24(18−x)(18−x)(18+x)=1\frac{24(18 + x)-24(18 - x)}{(18 - x)(18 + x)} = 1
(18−x)(18+x)
24(18+x)−24(18−x)
​
=1

⇒ 24(18+x−18+x)(18−x)(18+x)=1\frac{24(18 + x - 18 + x)}{(18 - x)(18 + x)} = 1
(18−x)(18+x)
24(18+x−18+x)
​
=1

⇒ 24(2x)324−x2=1\frac{24(2x)}{324 - x^2} = 1
324−x
2

24(2x)
​
=1

⇒ 324−x2=48x324 - x^2 = 48x324−x
2
=48x

⇒ -x² - 48x + 324 = 0

⇒ x² + 48x - 324 = 0

⇒ x² - 6x + 54x - 324 = 0

⇒ x (x -6) + 54(x - 6) = 0

⇒ (x + 54)(x - 6) = 0

For the equation to be 0,

Either,

⇒ x + 54 = 0 (or) x - 6 = 0

⇒ x = -54 (or) x = 6

⇒ x = 6 (As speed can't be negative, x ≠ -54)

∴ The speed of the stream is 6 kmph

HOPE IT HELPS UH
BYE
SEE UH AGAIN!!!!!

Answer 2

Answer:

6 km/hr

Step-by-step explanation:

Let the Speed of the stream be 'x' km/hr.

Given that Speed of the boat in still water = 18 km/hr.

Then,

Speed of the boat upstream = 18 - x.

Speed of the boat downstream = 18 + x.

∴ Time = Distance/Speed.

Given that distance between them is 24 km.

Time taken to go upstream = (24)/18 - x

Time taken to go downstream = (24)/18 + x.

Now,

Since, it takes 1 hour more to go upstream, we have

⇒ (24/18 - x) - (24/18 + x) = 1

⇒ 24(18 + x) - 24(18 - x) = (18 - x)(18 + x)

⇒ (432 + 24x - 432 + 24x) = 324 - x²

⇒ 48x = 324 - x²

⇒ x² + 48x - 324 = 0

⇒ x² + 54x - 6x - 324 = 0

⇒ x(x + 54) - 6(x + 54) = 0

⇒ (x + 54)(x - 6) = 0

⇒ x = -54, 6.

Since, speed cannot be negative. x ≠ -54.

Therefore, Speed of the stream = 6 m/hr.

Hope it helps!