Question

Greg swam 4 kilometers against the current in the same amount of time it took him to swim 16 kilometers with the current. The rate of the current was 3 kilometers per hour. How fast would Greg swim if there were no current?

Answer 1

5 kmph

Explanation:

Given: Greg swam 4 kilometers against the current.

Greg swam 16 kilometers with the current.

Rate of the current was 3kmph.

Lets assume the speed of greg swimming with no current be "x".

∴ Speed of swimming against current=
`(x-3)\ kmph`

Speed of swimming with current=
`(x+3)\ kmph`

As given, it took same amount of time to swim both with current and against current.

∴ Forming an equation to find the value of x, which is speed of greg swimming with no current.

We know,
`Time= (Distance)/(Speed)`

⇒
`(4)/((x-3)) = (16)/((x+3))`

Multiplying both side by (x+3) and (x-3)

⇒
`4* (x+3)= 16* (x-3)`

Using distributive property of multiplication.

⇒
`4x+12= 16x-48`

Subtracting both side by 4x and adding by 48.

⇒
`60= 12x`

Dividing both side by 12

⇒
`x= (60)/(12) = 5\ kmph`

Hence, Greg can swim at the rate of 5kmph with no current.