All you math gurus, please help me out!!!?

Question

What mass of methanol in kg (density = 0.791 g/mL) does it take to exactly fill a 17.8 gal tank given that 1 gal = 3.785 L?
Do not enter units with your answer.

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Is 53.22 the right answer?

Answer 1

When you know what units your answer needs to be in, you can figure it out by a process of cancellation of units, which allows you to determine whether you should multiply or divide by the various numbers.

x = (1 kg/1000 g)(0.791 g/mL)(1000 mL/L)(3.785 L/1 gal)(17.8 gal)

All units cancel except for kg, which you say you aren't including in the answer for some reason, and the two 1000s cancel, leaving...

x = 0.791 * 3.785 * 17.8 = 53.3 (rounded to three significant digits because two of your terms only have three significant digits)

Answer 2

Since 1 gal = 3.785L then 17.8 gal = 17.8 x 3.785
= 67.373 L
= 67373 mL
Mass of methanol = 0.791 x 67373
= 53292.043 g
= 53.29 Kg

Answer 3

ok, convert 17.8 gal to litres:
17.8gal x (3.785L/1gal) = 67.373L

convert litres to mL (1000mL = 1L)
= 67.373 x 1000 = 67373mL

mass = density x volume
= 0.791 g/mL x 67373 mL
= 53292.043 g

1000g = 1kg
mass = 53292 / 1000
= 53.29kg

Answer 4

(0.791 kg/L)(3.785 L/gal)(17.8 gal)=______ kg

53.29 depending on when you round anything.

Answer 5

(17.8 gal)(3.785 L/ gal.)(0.791 g/ mL)(1 kg/1,000g)(1,000 ml/ L) = 53.292