Question

Everyday Math

426. Heating Oil A 275 gallon oil tank costs $400 to fill. How much would it cost to fill a 180 gallon oil tank?

Answer 1

261.81818181

Explanation:

400÷275=x

x×180

Answer 2

If 275 gallon of oil tank costs $400 to fill.

Then 180 gallon of oil tank costs $261.8 to fill.

Explanation:

• Given that a 275 gallon of oil tank costs $400 to fill.

• We need to find how much it would cost to fill a 180 gallon oil tank.

• Use the unitary method to find the answer.

Step 1 of 2

If 275 gallon of oil tank costs $400 to fill.

Then the cost to fill 180 gallon of oil tank can be found by forming a proportion.

Let the required cost be x.

`$$\begin{aligned}\frac{\text { cost }}{\text { Gallons of Gas }} &=\frac{\text { cost }}{\text { Gallons of Gas }} \\(\$ 400)/(275) &=(x)/(180)\end{aligned}`

Multiplying both sides by 180 we get,

`$$\begin{aligned}(\$ 400)/(275) * 180 &=(x)/(180) * 180 \\x &=(\$ 400)/(55) * 36 \\x &=\$ 261.8\end{aligned}$$`

Step 2 of 2

To check if the answer is reasonable, we substitute it back in the formed proportion

`$(\$ 400)/(275)=(x)/(180)$$`

We found x=$261.8 hence,

`$(\$ 400)/(275)=(\$ 261.8)/(180)$$$\$ 1.45=\$ 1.45$$Here, $L H S=R H S$`

Hence, our answer is correct.