### Home > INT2 > Chapter 4 > Lesson 4.1.3 > Problem4-31

4-31.

You are feeling impulsive, so you are going to have the owner of the pet store randomly pick a fish for your aquarium at home. Homework Help ✎

1. A tank at the pet store contains $9$ spotted guppies, $14$ red barbs, $10$ red tetras, and $7$ golden platys. What is the probability (expressed as a percent) of getting a red fish from this tank?

How many red fish are in the tank? How many total fish are in the tank?

$\frac{14+10}{9+14+10+7}$

2. In a different tank that contains only golden platys, the probability of getting a female fish is $30\%$. If there are $18$ female fish in the tank, how many total fish are in the tank?

If $x$ = number of total fish in the tank

$\frac{18}{x}=\frac{30}{100}$