Principles of Counting : Solved Example 2/4 (Rule of And/Or)

[@onlinemathematicslectures9315]

Mam how many 2 digits can be formed when repetation is not allowed is it 10×9 or 9 ×9

[@Maha.salim1]

Good

[@JemalYesuf-po6lz]

I hate the last advertisement which says paper fold pyramid it masks the last answer