Which equation can be used to find the answer? an aquarium worker removed 78 fish from a tank. there were still 186 fish left in the tank. how many fish were in the tank before any were removed?
 a. f ÷ 2 =78 f = 156 156 fish
 b. f ÷ 2 =186 f = 372 372 fish
 c. f – 78 = 186 f = 264 264 fish
 d. f + 78 = 186 f = 108 108 fish?