If you’re given a number, subtract 1, then 2 from the result, then 3 from that result and so on until you reach 0 or a negative number.
For example, if you’re given 15:
15 – 1 = 14
14 – 2 = 12
12 – 3 = 9
9 – 4 = 5
5 – 5 = 0
Which of these numbers will finish exactly at zero?
102 103 104 105 106