26
It is: 81
36
Let's list the requirements for the mystery number: One's digit more than the ten's digit. Composite number. Two digits. Even number. Is two less than a square. Now that we've listed the requirements, let's look for a place to "attack" the problem. The easiest is probably to look at squares since our mystery number is two less than a square. Here are the first few squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100 and 121. Since our mystery number is 2 less than a square, let's go through that. -1, 2, 7, 23, 34, 47, 62, 79, 98, 119. Now we'll look at two things at once; we'll look only at the 2-digit numbers that are even. (We don't have to look at the "composite number issue" because every even number except 2 is composite since it can be divided by 2.) 34, 62, and 98. Now the number with the one's digit greater than the ten's digit - and there's only one of them: 34. The number 34 has a one's digit greater than the ten's digit, is composite, has two digits, is even, and is 2 less than a square.
The ones digit is 5 less than 10 (10-5=5) The tens digit is 2 more than the ones digit (5+2=7) The entire number is less than 200. It could be either "75" or "175", but is probably "175" or they would have said that the entire number was less than 100.
The only prime number less than 3 is 2.
26 5*5 and 3*3*3
87 is the only 2-digit number that is 6 greater and 13 less than a square, but it is not prime.
2 digit number which is square number less than 42 but greater than 29 = 36square numbers are 2, 9, 16, 25, 36, 49,...
It is: 81
the number is 24.. 24 is one less than 25 which is 5 squared when doubled its 48, which is one less than 7 squared (49)
36
there is no number less than 49 between 1 and 100 that if multiplied by 2 will have a 3-digit product no number less than 50, actually
26
something I don't know
Since there are so few options, trial and error/enumeration would be the way to go here.The 2-digit squares are: 16, 25, 36, 49, 64, 81, 100. The 2-digit cubes are: 27, 64.The only place where the difference between two of these numbers is 2, occurs between 25 and 27, thus the 2-digit number asked for is 26.
123
1,0002 = 1,000,000 so 1 less is 9992 = 998,001