Grandma Olga has 3 daughters and 3 sons. If all her daughters each have 6 sons, and each of her sons has 5 daughters, how many grandchildren does she have in total?
Let's be accurate as possible and think first.
33
From her daughters, Olga has 3 x 6 = 18 grandsons.

From her sons, she has 3 x 5 = 15 granddaughters.

Altogether, Olga has 18 + 15 = 33 grandchildren.

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Thus, the answer is 33