Question

You have written down all integers numbers from 1 to n on a blackboard, using different colors for different digits and same colors for same digits. That is, all zeroes on the blackboard have the same color, all ones on the blackboard share their own color as well, and so on. Unfortunately, your friend is colorblind and can only see 0s and 1s on the blackboard. How many numbers can he see completely (without any digits missing)?

Answer 1

Infinite

Explanation:

Your friend can see only 0 and 1 digits.That means he can only see integers with only 0 and 1 digits completely. from the question,it says you wrote down all integers from 1 to n.The set of integers are infinite. Also the set of Integers which have just 0 or/and 1 are also infinite.