A tank is 25% full of oil. The oil consists of 25% WTI Crude Oil and 75% Brent Crude Oil. 2/3 rd of the remainder of the tank is filled with 400 barrels of WTI Crude Oil. How much WTI Crude Oil is in the tank?
Choose the correct option:
A) 425 barrels B) 437.5 barrels C) 450 barrels D) 500 barrels E) 650 barrels
The tank was 25% full. Then, 2/3 rd of the remainder of the tank, so 2/3 rd of 75% of the tank, was filled with 400 barrels of WTI Crude Oil. 2/3 rd of 75% is 50%, thus we are told that 50% of the tank amounts for 400 barrels, which makes the capacity of the tank 800 barrels.   Therefore, initially, the tank had 0.25∗0.25∗800=500 barrels of WTI Crude Oil. After 400 barrels of WTI Crude Oil were added the amount of WTI Crude Oil became 50+400= 
<gadget id="calculator">50+400</gadget>
<output>450</output>
450 barrels.   Answer: 450 barrels.
<result>C</result>
A tank is 25% full of oil. The oil consists of 25% WTI Crude Oil and 75% Brent Crude Oil. 2/3 rd of the remainder of the tank is filled with 400 barrels of WTI Crude Oil. How much WTI Crude Oil is in the tank?