Question #89c39

1 Answer
Sep 26, 2017

20 and 5.

Explanation:

Let the speed of the boat be x "miles/hour" and the speed of the current be y "miles/hour".

In down stream the trip (x+y) "miles" takes in 1 hour. so, 825 "miles" takes 825/(x + y) "hours".

Hence, as per question

825/(x + y) = 33" "" "(i)

Again, in the trip back, (x - y) "miles" take 1 hour. Hence 825 "miles" take 825/(x - y) "hours".

Hence, as per question

825/(x - y) = 55" "" "(ii)

From equation (i), we get

825/(x + y) = 33

or

x + y = 825/33 = 25" "" "(iii)

From equation (ii), we get

825/(x - y) = 55

or

x - y = 825/55 = 15" "" "(iv)

Now, solving equations (iii) and (iv), we get

x = 20 and y = 5

Hence, the speed of the boat is "20 miles/hours" and the speed of the current is "5 miles/hours".