Solution Step 0/0
On every birthday since I was born, I have had a cake decorated with the appropriate number of candles. I have blown out 210 candles so far. How old am I?
Explanations
The answer is 20 years old because 210 is the twentieth triangular number, equal to the sum of all the numbers from 1 to 20.Check 18
Check 19
Check 20
Check 21
