If 7 gallons of gasoline are added to a tank that is already filled to 3/4 of its capacity, the tank is then filled to 9/10 of its capacity. How many gallons does the tank hold?
Choose the most appropriate option
A) 20
B) 24
C) 36
D) 42
E) 60
Let the Capacity of the tank=C   (3/4)C + 7 = (9/10)C   =&gt;(9/10)C - (3/4)C = 7   =&gt;(3/20)C = 7   =&gt;C = (7*20)/3 = 46.66   Number of gallons of gasoline that the tank currently holds = 3/4*C +7 = 34.99+7= 
<gadget id="calculator">34.99+7</gadget>
<output>41.99</output>
41.99=42   Answer 42
<result>D</result>
If 7 gallons of gasoline are added to a tank that is already filled to 3/4 of its capacity, the tank is then filled to 9/10 of its capacity. How many gallons does the tank hold?