Doesn’t 11 have two 1s ?One on the tens digit and one on the units digit? Why does the answer says that 11only have 1s on the tens digit?


@smilingtadpole1 In this problem, we do not care whether 11 has one or two 1s. What matters is the fact that 11 contains a 1. When you solved this problem, you assumed that because 11 had two ones, it should be counted twice, which is incorrect. I hope this helps!(also charge your device lol)