Iam a number betwee 60 and 100 my ones digit is two less than my tens digit i am a prime number what number am 1?

Tens digit = x 
units digit = x-2 
Number = 10x+x-2 = 11x-2 
Lowest x = 6 number 64 is not prime 
x = 7 75 is not prime 
x = 8 86 is not prime 
x = 9 97 is prime 
Answer 97

Let's name the digit: 

x- ones digit
y - tens digit

we know that x=y-2. 

Now, y can be 6,7,8,9 (the number is between 60 and 100 (so depending on your understanding of "between", 0 is also possible. but then the number would have to have -2 as its ones digit, so in any case, it's not possible). 

So the possibilities with x=y-2:

64
75
86
97
Out of those 64 and 86 are even, so they can't be prime. 
75 has 5 in its ones number: it's divisible by 5. 

so the correct answer is 97. 

Look at this and see if it

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)