Aaron, Henry's brother, is 15 years old. Henry's sister is three times as old as Aaron. Henry is four times as old as his sister. What's the combined age of the siblings?
Step-by-step reasoning:
240
If Aaron is 15 years old, and his sister is 3 times as old as him, then the sister is 3 * 15 = 45 years old.

Together, Aaron and his sister have a total age of 45 + 15 = 60 years.

Henry is four times as old as the sister, meaning he is 45 * 4 = 180 years old.

The three siblings together have a total age of 60 + 180 = 240 years.

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So, the answer is 240