Ask Marilyn: When Are You Twice as Old as Your Child?

Jim Hurst of Coatesville, Pa. writes:

Marilyn: There is only one time in your life when you’re twice as old as your child. When is that?

Marilyn responds:

This is actually a fun logic­—not math—question, readers. Think about it awhile before checking the answer; it ­appears at the end of the ­column.

Miles Klein of Frisco, Tex. writes:

Marilyn: Why do ice cubes melt faster when you pour cold water on them?

Marilyn responds:

Even though the water is cooler than the surrounding air, water is much denser (has more particles per unit ­volume) than air. So as water is much warmer than ice, anyway, its many particles—and in this case, they’re flowing, too—warm it faster than the air would alone.


Answer: When the child reaches the age you were when he or she was born. You’ll stay “twice as old” until your next birthday.