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+---- Thread: Simple Math Problem - It's been a while... (/Thread-Simple-Math-Problem-It-s-been-a-while)
Simple Math Problem - It's been a while... - NJGx03x871 - 06-29-2014
What's the proper way to solve this problem?
Quote:If a car uses 1 1/2 gallons of gas every 30 miles, how many miles can be driven with 6 gallons of gas?
Simple Math Problem - It's been a while... - alram - 06-29-2014
divide
6 gal/1.5 gal=4 gal
multiply
4 gal x 30 miles=120 miles
Simple Math Problem - It's been a while... - KayV - 06-29-2014
Alram is correct. Another way to think about it:
If the car goes 30 miles in 1.5 hours, you can double both those numbers to get 60 miles in 3 hours. Then double again to get 120 miles in 6 hours.
Simple Math Problem - It's been a while... - NJGx03x871 - 06-29-2014
alram Wrote:divide
6 gal/1.5 gal=4 gal
multiply
4 gal x 30 miles=120 miles
Thanks!
KayV Wrote:Alram is correct. Another way to think about it:
If the car goes 30 miles in 1.5 hours, you can double both those numbers to get 60 miles in 3 hours. Then double again to get 120 miles in 6 hours.
You guys are awesome! The qualifying test that I'm studying for will be timed and little "tricks" like this will help!
If you don't mind, I have another basic algebra question:
Quote:An airplane flying a distance of 875 miles used 70 gallons of gasoline. How many gallons will it need to travel 3000 miles?
I believe it's something like this, but I can't remember how to manipulate it into a solvable equation:
875/70 = 3000/x
Can you run me through this step-by-step?
Simple Math Problem - It's been a while... - bluebooger - 06-29-2014
cross multiply
just keep your units the same (gallons, miles, grams, light years,
keep them the same and it all works out
Code:
(1.5/30) = (6/x)
1.5 gallons 6 gallons
------------ = ----------
30 miles x miles
1.5 * x = 30 * 6
1.5 * x = 180
x = 180/1.5
x = 120Simple Math Problem - It's been a while... - Lindagerr - 06-29-2014
bluebooger Wrote:cross multiply
just keep your units the same (gallons, miles, grams, light years,
keep them the same and it all works out
Code:(1.5/30) = (6/x)
1.5 gallons 6 gallons
------------ = ----------
30 miles x miles
1.5 * x = 30 * 6
1.5 * x = 180
x = 180/1.5
x = 120
You can do the same for your last question
cross multiply and divide
875 whatnot 3000 whatnot
------ = ------
70 thingies x thingies
3000 X 70 = 210,000
210,000 divided by 875 = 240
X = 240