Winnie wrote the following riddle.i am a number between 60 and 100.my ones digit is two less than my tens digit.i am a prime number.

79

Step-by-step explanation:

60<xy<100

y -2 =x

if it is prime

y cannot be even

so y could be      1,3,5,7,9

x would then be 9,1,3,5,7

but to be between 60 and 100

x must be 7 or 9

so the number must be 79 or 57

57 is not prime so

the number is 79

3 (x -2) = 22 -x

4x -6 = 22

4x = 28

x = 7

Only one solution exists

Step-by-step explanation: