A car needs 3 gallons of gas every 70 miles. how much gas would it need for 105 miles?

Question

I tried dividing 3 gallons by 70 miles to get the miles per gallon but it docent help.

Answer 1

Hey Alice -- half of 70 miles is 35 ... adding half to 70 gets 105mi ...

 

half of 3 gal is 1.5 gal ... adding half to 3 means 4.5 gal ... Best wishes, ma'am :)

Answer 2

Hi Alice;

(3 gallons)/(70 miles)=(x gallons)/(105 miles)

Please note, both sides are in the units of gallons/miles.  These cancel.

(3 gallons)/(70 miles)=(x gallons)/(105 miles)

3/70=x/105

We are now ready to perform calculations.

Let's multiply both sides by 105...

(105)(3/70)=(x/105)(105)

4.5=x

The car needs 4.5 gallons.

Answer 3

(3 gallons/70 miles) * 105 miles

(315 gallons * miles) / 70 miles

 

315 gallons/70 = 4.5 gallons.