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

Answer:

5 kmph

Step-by-step 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, $Time= \frac{Distance}{Speed}$

⇒ $\frac{4}{(x-3)} = \frac{16}{(x+3)}$

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

⇒$4\times (x+3)= 16\times (x-3)$

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

⇒$x= \frac{60}{12} = 5\ kmph$

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