There cannot be a proper three digit number between 10 and 20. It must be a two digit number. If you consider a 2-digit number between 10 and 20, then its tens digit MUST be 1 and so MUST be odd.
So most of this question is either wrong or irrelevant. Are you sure you have not cut and pasted bits from two questions?
Meaningless question.
The largest three digit prime number whose digits are all primes is 773.
49 = 72 16 =4^
The prime number between 20 and 30 whose ones digit is 7 greater than its tens digit is 23. The tens digit is 2, and the ones digit is 3, which is 7 greater than 2. Additionally, 23 is a prime number because it is only divisible by 1 and itself, with no other factors.
992
889
Meaningless question.
The largest three digit prime number whose digits are all primes is 773.
Nine hundred thirty (930) is the highest three digit number whose digits have a sum of 12. 9+3+0=12. Any numbers higher than that will give you an sum greater than 12.
What is the units digit of the least whole number greater than 1000 whose digits are all different?
49 = 72 16 =4^
The prime number between 20 and 30 whose ones digit is 7 greater than its tens digit is 23. The tens digit is 2, and the ones digit is 3, which is 7 greater than 2. Additionally, 23 is a prime number because it is only divisible by 1 and itself, with no other factors.
961
992
940
97 is one example.
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