Riddle: A mathematician wrote a 2-digit number on a sheet of paper. When he turned the sheet upside down, the number decreased by 75. What was the number?

This riddle has been around for some time on internet platforms such as Instagram, Facebook, and WhatsApp, and many people still argue over what the answer might be, as there are many possibilities.

The answer to the A mathematician wrote a 2-digit number on a sheet of the paper riddle is a 75.

91, if we turned the sheet upside down this number will become 16 whose difference is 75.

Some of the numbers that are still valid if you turn them upside down are 1, 6, 9, 8. A combination of two digits is 91 as the decrease we want to achieve is 75. 91-16=75

The number was 91,when turned upside down became 16—the diff being 75