plz tell me the answer of this question ☝️☝️ ..fast..
Answers
Both answers are same
Let the actual speed of the man be x km/hr and y be the actual time taken by him in hours.
So, we know that
Distance covered = speed x distance
⇒ Distance = x × y = xy …………(i)
First condition from the question says that,
If the speed of the man increase by 1/2 km/hr, the journey time will reduce by 1 hour.
Showing this using variables, we have
⇒ When speed is (x + 1/2) km/hr, time of journey = y – 1 hours
Now,
Distance covered = (x + 1/2) x (y – 1) km
Since the distance is the same i.e xy we can equate it, [from (i)] xy = (x + 1/2) x (y – 1)
And we finally get,
-2x + y – 1 = 0 ………………(ii)
From the second condition of the question, we have
If the speed reduces by 1 km/hr then the time of journey increases by 3 hours.
⇒ When speed is (x-1) km/hr, time of journey is (y+3) hours
Since, the distance covered = xy [from (i)]
xy = (x-1)(y+3)
⇒ xy = xy – 1y + 3x – 3
⇒ xy = xy + 3x – 1y – 3
⇒ 3x – y – 3 = 0 ……………… (iii)
From (ii) and (iii), the value of x can be calculated by
(ii) + (iii)
⇒ x – 4 = 0
x = 4
Now, y can be obtained by using x = 4 in (ii) -2(4) + y – 1 = 0
⇒ y = 1 + 8 = 9
Hence, putting the value of x and y in equation (i), we find the distance
Distance covered = xy
= 4 × 9
= 36 km
Thus, the distance is 36 km and the speed of walking is 4 km/hr.
