Answer:
16
Step-by-step explanation:
Let's assume that Nancy bought 'p' numbers of platies. The question says, she buys goldfish, 4 more than twice the number of platies.
So, 4 more than twice of 'p' can be written as,
that is the number of goldfish she bought. Let 'g' represent the number of goldfish. So we have,
She also buys 2 black mollies and a few guppies that amounted to one quarter of the total number of goldfish she bought. Let 'x' represent the number of guppies, so we have,
Altogether she has 35 fish, so the sum of all the fishes should be 35,
multiplying both the sides of the equation by 4, we get,
Hence, Nancy bought 8 platies. Now that we know the number of platies, we can find the number of goldfish that she bought.
We know that she bought (2p+4) number of goldfish, putting the value of 'p', we get,
Hence, Nancy bought 20 goldfish for her aquarium.