Jack has $800,000 in his pocket nothing but cash, but he spent 700,000 on parts for his plane. Jack is planning a road trip back home. if gas is $400 a gallon and his trip is 600 miles, will he make it home?

Guest Jun 18, 2015

#2**+10 **

Thanks Chris

I had to think quite hard about this - maybe I shouldn't admit that :))

He has a maximum of $100,000 for fuel

Fuel costs $400 per gallon so he has enough money for

100,000 / 400 = 250 gallons

Now the distance is 600 miles so it will be alright so long has he gets at least

$$\frac{600\;miles}{250\;gallons}=\frac{2400\;miles}{1000\;gallons}=2.4miles/gallon$$

Just like Chris said

Melody
Jun 19, 2015

#1**+10 **

As long as this inequality is satisfied, he can make it back home.....

($400)( 600) / x ≤ $100,000 where x is the mpg of gas that his car gets ......so.....rearranging

240,000/100,000 ≤ x

2.4 ≤ x

In other words, as long as his car gets at least 2.4 mpg of gas, he can make it back

CPhill
Jun 18, 2015

#2**+10 **

Best Answer

Thanks Chris

I had to think quite hard about this - maybe I shouldn't admit that :))

He has a maximum of $100,000 for fuel

Fuel costs $400 per gallon so he has enough money for

100,000 / 400 = 250 gallons

Now the distance is 600 miles so it will be alright so long has he gets at least

$$\frac{600\;miles}{250\;gallons}=\frac{2400\;miles}{1000\;gallons}=2.4miles/gallon$$

Just like Chris said

Melody
Jun 19, 2015