Question

A mule deer can run 1/4 of a mile in 25 seconds. At this rate, which expression can be used to determine how fast a mule deer runs in miles per hour?
a. 25 seconds/ 1/4 of a mile= 36 miles per hour
b. 1/4 of a mile / 25 seconds= 36 miles per hour
c. 1/4 of a mile / 25 seconds= 100 miles per hour
d. 25 seconds/ 1/4= 100 miles per hour
@ganeshie8 @SandeepReddy

Answer 1

so, what decimal of a mile is 1/4 of a mile?

Answer 2

um is it 0.25

Answer 3

yea, ok, so that just makes setting this up more convenient, so now you have \[\frac{.25 miles}{25 seconds}\times \frac{? seconds}{?minute}...\]

Answer 4

how many seconds does an hour has? 60x60=360 seconds once you have that you do cross multiplication

Answer 5

so now, we need to go from seconds to hours, the first step(if you don't know off the top of your head how many seconds are in an hour) is to find the conversion factor, so how many seconds are in a minute?

Answer 6

i meant 3600 sorry

Answer 7

60 seconds

Answer 8

ok so now, we just fill in the question marks

Answer 9

\[\frac{.25 miles}{25 seconds}\times \frac{\color\red{60} seconds}{\color\red{1}minute}...\]

Answer 10

so, once we multiply that out we would be left with miles per minute as our units, can you guess how we will go from minutes to hours?

Answer 11

umm.. I don't know sorry

Answer 12

ok, so take a look at how we went from seconds to minutes

Answer 13

we set up a fraction, that is equivalent to one. using something called a conversion factor(ie, there are 60 seconds in one minute)

Answer 14

so we are trying to go from minutes to hours, can you think of what the conversion factor may be?

Answer 15

60?

Answer 16

60 what? you have to include units

Answer 17

just use words,

Answer 18

is it 60 seconds?

Answer 19

well, we want to go from \(\color\orange{minutes~ to~ hours}\), so, since we have already converted seconds to minutes, we do not need another seconds.

Answer 20

so what did we need to go from seconds to minutes?

Answer 21

is it minutes to hours?

Answer 22

please don't guess, if you don't know just say it. It's a lot harder to explain when you do.

Answer 23

im sorry I didn't know :(

Answer 24

it's ok, so I take it, you are a little lost on the topic? Have you been able to follow what I have said so far?

Answer 25

yes so how much do we have left to complete the question

Answer 26

A lot, if you do not understand, please read this http://www.purplemath.com/modules/units.htm

Answer 27

it explains the process we need to perform

Answer 28

I understand :)

Answer 29

then what do we need to know to go from minutes to hours?

Answer 30

is it like this? 60 seconds : 1 minute
60 minutes : 1 hour
1 mile : 5280 feet
1 foot : 12 inches
2.54 centimeters : 1 inch
100 centimeters : 1 meter

Answer 31

@GretaKnows can you help me with this question please?

Answer 32

well, those are conversion factors, but you only need to go from miles/second to miles/hr

Answer 33

so you do not need all of them. This is not just one multipliction but teo

Answer 34

ok :)

Answer 35

so you should have enough information between the website and the work here to do the problem now. Please try

Answer 36

sorry I wasn't on my computer last night!!