All the numbers from 1 to 99 are multiplied together. Use a pattern to determine the last digit of the product. Justify your answer.

Answer 1

It's a very simple pattern, really. :-)

Think what happens to the last digit of any number when multiplied by ten.

Answer 2

im sorry but i do not understand :(

Answer 3

Take any digit, say 2.

Multiply it by 10.

What's the last digit?

Multiply that by anything else. What's the last digit?