A small zoo houses a variety of 68 wild animals. After they send a gorilla family of six to a different zoo, they adopt a hippopotamus from another zoo. A while later, an animal rescue contacted them, and the zoo took in three endangered rhinos. Then one of their lionesses gave birth to cubs, and they opened a meerkat exhibit with twice as many meerkats as they had gained lion cubs. The zoo then had 90 animals in all. How many lion cubs were born at the zoo?
A step-by-step solution is:
8
Let C be the number of lion cubs.

There are 2C meerkats in the new exhibit.

The zoo sent 4 gorillas away, so they had 68 - 6 = 62 animals left.

They adopted a hippopotamus, so they had 62 + 1 = 63 animals.

They took in 3 rhinos, so they had 63 + 3 = 66 animals.

Thus, they had 90 - 66 = 24 new lion cubs and meerkats.

Therefore, they had C + 2C = 3C = 24 new lion cubs as meerkats.

Hence, there were C = 24 / 3 = 8 lion cubs born.

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Thus, the answer is 8