Question

Winnie write the following riddle.I am a number between 60 and 100.My ones digit is teo less than my trns digit.I am a prime number.Winnie's friend Marci guessed that her riddle was about the number 79.Why can't 79 be the answer to Winnie's riddle?

Answer 1

The criteria is
Between 60 & 100
Units digit 2 less than tens
Prime number

79 is a number between 60 & 100 and it is a prime number (as its only factors are 1 and itself), however 79 has a tens digit that is 2 less than the units - not the units 2 less than the tens.
As it does not comply with one of the rules the number cannot be 79

The number that would work is 97