Alvarito wrote:
Bunuel wrote:
bmwguy wrote:
I did the problem differently. Is this a solid approach?
5 hours at 50 MPH, the car will travel 5*50=250 miles
Total capacity of the tank is 12 gallons. At 50 MPH, the car uses 30 miles per gallon.
30*12 = 360 gallons total
\(\frac{250 miles driven}{360 miles tank} = \frac{25}{36}\)
The answer is correct but the reasoning is not.
We are told that the car uses 1 gallon of gasoline every 30 miles, so 12 gallons (full tank) of gasoline is enough to travel 12*30=360 miles. Since the car traveled only 250 miles, then it used 250/360=25/36 of full tank.
Hope it's clear.
I did it in another way, but I'm not sure if I did it right.
the car spends 1 gallon every 30m, so 2g every 1h, the problem says the drove for 5h(that mean 10g of fuel consume)
now we are told the full tank is 12g.
now we have what we spent over what we had: 10/12= 5/6 (but i don't have this option but the same with option E, multiplying each side by the same number.
can anyone help me out to know if i'm right doing this proble,
Bunuel please.
He travel 50 miles an hour using 1 gallon per 30 miles.
Taking LCM of 30&50 = 150
That means he will use 5 gallon for 3 hour drive.
Or 1.666 gallon for 1 hour.
For 5 hours he will use 5*1.66 gallon = 8.33 gallons
Which is 8.33/12 gallon of total
Or 25/36 gallon of total.
You can't round figure 1.66 to 2 gallon an hour. It will create a serious gap between usage and consumption.
Posted from my mobile deviceThanks for the help. now i know what i did wrong, i read 30 minutes instead of 30 miles, he drive 5h for 50 miles per hour, spending 1gallon every 30 miles (i thought 1g every 30 minutes).