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 think first. Chain of thought:
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.
Therefore, the answer is 33.