Math PLEASE HELP
posted by Bri on .
MS Wilkens went to the gas station to fill her car. Her gas tank is 20% full.
The cost of gas is $4.29 per gallon. How much will itcost to fill the tank? Use the conversion 1 gallon=231 in cubed.
They showed a pic. of a tank with length=1.75ft
width=1.25 ft
height=11 in
I did v=bh
v=lwh v=1.75(1.25)11 v=24.0625 ft cubed
12 in=1ft
24.0625(12)=288.75 in cubed
288.75 in cubed/213 in cubed= 1.25 gallons
now I am cunfused
80% of 1.25= gallons left to fill tank
.80(125)= 1 gallon left to fill tank
1 gallon =$4.29 It will cost$4.29 to fill the tank
PLEASE HELP, did I do this correctly.

you cannot convert ft^3 to in^3 by multiplying by 12.
1 ft = 12 in, so
1 ft^3 = (12 in)^3 = 1728 in^3
24.0625 * 1728 = 415890 in^3 = 180 gal
That's some tank!
Ahh! You also did the volume wrong. You need to measure everything in either feet or inches, and you mixed them together.
Let's start over. The volume of the tank in in^3 is
21*15*11 = 3465 in^3 = 15 gals.
Now you should be able to make things come out right. 
Ok I corrected my mistake and got that it would cost $51.48, because it was 15 gallons she needed to get.
Is this correct now? Thank you 
Looks good to me.