cats and dogs

To solve the maximum number of animals adopted, we want to maximize the number of dogs in the adoption center since a higher percentage of them were adopted. Therefore, we want the highest integer 55 or less that is perfectly divided by 4 where the number of cats are divisible by 5.

Maximizing the number of dogs is the same as minimizing the number of cats. That is to say that 1 cat adoption means there were 5 cats there and therefore 50 dogs. That doesn't work though because 50 isn't divisible by 4. Then we'll step up the number of cat adoptions until it leaves a number of dogs divisible by 4

0 cat adoptions (0 cats) = 55 dogs
1 cat adoption (5 cats) = 50 dogs
2 cat adoptions (10 cats) = 45 dogs
3 cat adoptions (15 cats) = 40 dogs *** this works.

To answer the question then, the answer is 13 [C], 3 cats and 10 dogs.

5 x dogs+ 4 x cats = 55

cat's number will end in digit zero so the only possibility are 0, 20 and 40

if 0 then adopted=11
if 20 then adopted=12
if 40 then adopted=13