Question 34
Emerald wrote on the blackboard all the integers from $1$ to $2011$. Then she erased all the even numbers.
a. How many numbers were left on the board?
b. How many of the remaining numbers were written with only the digits $0$ and $1$?
a. How many numbers were left on the board?
b. How many of the remaining numbers were written with only the digits $0$ and $1$?