The indicator of oil tank shows 1/5 full. when truck delivers 165 gallons oil, the indicator shows 4/5 full. What is the capacity ) of the tank?

Question

options in gallons are

55

145

105

275

plz explain properly

Answer 1

Since 165 gallons were delivered the tank must be at least 165 in capacity. Of the answers available only one answer is larger than 165, so the answer is 275.

Answer 2

Let x = the capacity (in gallons) of the tank

 

Then, (4/5)x - (1/5)x = 165

 

(3/5)x = 165

 

Multiply both sides by 5 to get 3x = 825.

 

Divide both sides by 3.  So, x = 275 gallons

 

The capacity of the tank is 275 gallons.