Question

Rahamatchacha covers 30 miles in 6 hours in downstream and returns the same distance in
10 hours in upstream by his boat. Let us calculate and write the speed of Rahamatchacha's
boat in still water and the speed of the stream too.​

Answer 1

Answer: Speed of boat in still Water = 4 m / hr Speed of stream = 1 m / hr

Given:

Rahamatchacha covers 30 miles in 6 hours in downstream. And returns the same distance in 10 hours in upstream by his boat.

To Find:

• Speed of boat
• Speed of stream

Solution:

Let the speed of boat be x m / hr. Speed of stream be y m / hr.

According to the question,

(x + y) = 30/6

⟹(x + y)= 5 -------- (i)

(x - y) = 30/10

⟹ (x - y ) = 3 ----------- (ii)

subtracting both equations. [by method of elimination]

x + y = 5

x - y = 3

(-) (+) (-)

_________

0x + 2y=2

y=2/2

y=1

putting the value of y in equation 1, we get

x + 1 = 5

⟹ x = 5-1

⟹ x = 4

Hence, Speed of boat in still Water = 4 m / hr Speed of stream = 1 m / hr