In seans fish tank, there are 6 times as many goldfish as guppies. There are a total of 21 fish in the tank. How many more goldfish are there than guppies?

you can do 3x6 and get 18, and what you have left over which is 3 that is how many guppies you have and if you do 18-3 you get 15 which is your answer

Answer Link

blahblahmali blahblahmali · Answer 2 · 2018-07-02T07:54:40-04:00

lets name the number of guppies in the tank as x
number of goldfish in the tank is 6 times the amount of guppies.
since the amount of guppies is x, then number of goldfish is 6 * x = 6x

therefore total amount of guppies and goldfish is x + 6x
there are total of 21 fish
therefore x + 6x = 21
7x = 21
x = 21/7
x = 3
therefore number of guppies = 3
number of goldfish -6x and x = 3 therefore 3 x 6 = 18 goldfish
we are asked to find how many more goldfish than guppies
we have to find the difference
18 - 3 = 15
there are 15 more goldfish than guppies