Question

A train travels 42 kilometers in 15 minutes.



How far will the train travel in 3 hours at that speed?









A.
168 km







B.
336 km







C.
504 km







D.
672 km
b?

Answer 1

@mathmale

Answer 2

I'd suggest you take the given info and write it as a "rate of change:"\[\frac{ 42~km }{ 15~\min }\]

Answer 3

3 hours = 180 minutes
180 minutes / 15 minute intervals is 12
12 intervals * 42 = 504
C

Answer 4

You could either use this rate as is, or you could reduce the numerical fraction.

To find the distance traveled in 3 hours, convert 3 hours to minutes, and then multiply the rate by that number of minutes. Or, convert 15 min to hours and multiply the resulting rate by 3 hours. Please show your work.

Answer 5

so 60/15=4 4*3=12 is that how u do it ?

Answer 6

@mathmale

Answer 7

@likeabossssssss look at my work, yes that is correct, then you multiply that by 42km

Answer 8

it would be 540km

Answer 9

In making the conversions we have to express the results in the proper units of measurement.\[\frac{ 42~km }{ 15~\min }*\frac{ 60~minutes }{ 1~hour }\]

Answer 10

ok

Answer 11

Then multiply this result by 3 hours. Ensure that the final units of measurement are Km.

Answer 12

4*3= 12 then times it by 42 like @xGuardians said?

Answer 13

Again, please show your units of measurement; without them, it's considerably harder to see what you're attempting.

\[\frac{ 42~km }{ 15~\min }*\frac{ 60~minutes }{ 1~hour }*3~hours\]

Answer 14

how do I show them

Answer 15

I've modeled use of the units of measurement as best I can in the work shared with you (above).

Answer 16

so 42km over 15mins times 60 mins over 1 hour times three?

Answer 17

Yes. it'd be better to "do the math" with the formula work I've given you instead of changing the problem back to words.

Start by cancelling units where possible; for example, cancel "minutes."

Again, please show your work and stick with formulas / expressions.