11th Class
Mathematics
Sample Paper
Mathematics Olympiad - Sample Paper-10
question_answer
An intelligence agency forms a code of two distinct digits selected from 0, 1, 2,..., 9 such that the first digits of the code is non-zero. The code, handwritten on a slip, can however potentially create confusion, when read upside down-for example, the code 91 may appear as 16. How many codes are there for which no such confusion can arise?