If you write down all the numbers from 1 to 100, then how many times do you write 3?

If you write down all the numbers from 1 to 100, then how many times do you write 3?

  • 3,13,23 (3 units)
  • 30,31,32,33,…,39 (11 units)
  • 43,53,63,73,83,93 (6 units)

Total: 3 units+11 units+6 units=20 units

Answer: 20