MathDB

In a room, there are

100

light switches, labeled with the positive integers

{1,2, . . . ,100}

. They’re all initially turned off. On the

i

th day for

1 \le i \le 100

, Bob flips every light switch with label number

k

divisible by

i

a total of

\frac{k}{i}

times. Find the sum of the labels of the light switches that are turned on at the end of the

100

th day.

Problem Statement