Aboat traveled 147 miles downstream and back. the trip downstream took 7 hours. the trip back took 147 hours. find the speed of the boat in still water and the speed of the current.

The speed of boat in still water is 11 miles per hour

The speed of current is 10 miles per hour .

Step-by-step explanation:

Given as :

The distance cover by boat in downstream = = 147 miles

The time taken by boat in downstream trip = = 7 hours

The distance cover by boat in upstream = = 147 miles

The time taken by boat in upstream trip = = 147 hours

Let The speed of boat in still water =   = x mph

And  The speed of the current =   = y mph

Now, According to question

Speed =

For downstream

+   =

or, x + y =  

I.e x + y = 21   mph              ..........1

For upstream

+   =

or, x - y =  

I.e x - y = 1   mph              ..........2

Now, Solving Eq 1 and 2

I.e (x + y) + (x - y) = 21 + 1

Or, (x + x) + (y - y) = 22

Or, 2 x = 22

∴  x =

I.e x = 11  mph

So, speed of boat = x = 11 miles per hour

Again, put The value of x in Eq 2

So,  x - y = 1   mph    

I.e   11 - y = 1

∴, y = 11 - 1

I.e y = 10 mph

So, speed of current = y = 10 miles per hour

Hence The speed of boat in still water is 11 miles per hour , and The speed of current is 10 miles per hour . Answer

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