Question

A submarine descended 3/5 of a kilometer in 1/5 of an hour. What was the submarine’s rate of descent in kilometers per hour?

Answer 1

Answer:

3 km per hour

Step-by-step explanation:

You can deduct the answer instinctively since both the distance and the time of the descent are expressed in /5... so you can just get rid of the '/5' in both instances to get the result: 3 kilometers in 1 hour.

But you can also find it easily using the cross-multiplication system:

$\frac{3}{5} km = \frac{1}{5} hour$

Then you multiply each side by 5 to get

3 km = 1 hour

Thus the rate of descent is of 3 km per hour.

Answer 2

Answer:

3 kilometer per hour

Step-by-step explanation:

We are given that a submarine descended 3/5 of a kilometer in 1/5 of an hour and we are to find the submarine's rate of descent in kilometers per hour.

$\frac{3}{5} kilometer = 0.6 kilometer$

$\frac{1}{5} hour = 0.2 hour$

Using the ratio method to find the rate of descent:

$\frac{0.6km}{x} =\frac{0.2hour}{1 hour}$

$x = \frac{0.6}{0.2}$

$x=3$

Therefore, the rate of descent of submarine is 3 kilometer per hour.