The aquarium has 6 fewer yellow fish than green fish. 40 percent of the fish are yellow. How many green fish are in the aquarium?
Let the number of green fish =G
The number of yellow fish =G - 6
0.4[G + G - 6] = G - 6, solve for G
G = 18 number of green fish
Check:
18 - 6 = 12 yellow fish.
18 + 12 = 30 fish in total
40% x 30 =12 number of yellow fish.
Let the number of green fish = G
Then the number of yellow fish = G - 6
The total fish in the tank = G + G - 6 = 2G - 6
And 40% of these are yellow ....so....
Yellow fish G - 6
________ = ______ = .40 multiply both sides by 2G - 6
Total fish 2G - 6
G - 6 = .40 (2G - 6) simplify
G - 6 = .8G - 2.4 add6 to both sides.....subtract .8G from both sides
.2G = 3.6 divide both sides by .2
G = 18 fish are green