Karen works at an animal shelter with 30 dogs, 28 cats, and 20 lizards. Every month, 50% of the dogs are adopted, 25% of the cats are adopted, and 20% of lizards are adopted. If the shelter takes in 13 new pets a month, how many pets are there after one month?
Let's think step by step below.
65
First find how many dogs get adopted each month by multiplying the number of dogs by their chance of getting adopted: 30 dogs * 50% = 15 dogs.

Then do the same thing for the cats: 28 cats * 25% = 7 cats.

And do the same thing for the lizards: 20 lizards * 20% = 4 lizards.

Now add up the number of each kind of pet to find the initial total number of pets: 30 dogs + 28 cats + 20 lizards = 78 pets.

Now subtract all the pets that get adopted in one month from the initial number of pets: 78 pets - 15 dogs - 7 cats - 4 lizards = 52 pets.

Now add the extra 13 pets the shelter takes in that month to find the final number of pets: 52 pets + 13 pets = 65 pets.

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The answer is 65