Total number of 2-digit numbers = (99 - 9) = 90 of themEvery number that isn't a perfect square has an even number of factors.2-digit numbers that are perfect squares: 16, 25, 36, 49, 64, and 81 = 6 of themRemaining 2-digit numbers = (99 - 6) = 93 .
6 is the only perfect digit. The next perfect number is 28.
25
A 3 or 4 digit number.
I am pretty sure you can figure this out on your own. Raise different numbers to the square, until you get a 4-digit result. Similary, calculate the cube of different numbers, until you get a 4-digit number. If you want the SAME number to be both a perfect square and a perfect cube, then it must be a power of 6. In that case, just experiment raising different numbers to the sixth power, until you get a 4-digit number.
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Total number of 2-digit numbers = (99 - 9) = 90 of themEvery number that isn't a perfect square has an even number of factors.2-digit numbers that are perfect squares: 16, 25, 36, 49, 64, and 81 = 6 of themRemaining 2-digit numbers = (99 - 6) = 93 .
I believe there are 2 positive three-digit perfect cube numbers, that are even.
6 is the only perfect digit. The next perfect number is 28.
102 = 100 which is the first possible three digit number that is a perfect square. 312 = 961 which is the last possible three digit number that is a perfect square. So there are 22 three digit positive numbers that are perfect squares.
25
A 3 or 4 digit number.
There are 28706 such combinations. 5456 of these comprise three 2-digit numbers, 19008 comprise two 2-digit numbers and two 1-digit numbers, 4158 comprise one 2-digit number and four 1-digit numbers and 84 comprise six 1-digit numbers.
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I am pretty sure you can figure this out on your own. Raise different numbers to the square, until you get a 4-digit result. Similary, calculate the cube of different numbers, until you get a 4-digit number. If you want the SAME number to be both a perfect square and a perfect cube, then it must be a power of 6. In that case, just experiment raising different numbers to the sixth power, until you get a 4-digit number.
There are 9 1-digit numbers and 16-2 digit numbers. So a 5 digit combination is obtained as:Five 1-digit numbers and no 2-digit numbers: 126 combinationsThree 1-digit numbers and one 2-digit number: 1344 combinationsOne 1-digit numbers and two 2-digit numbers: 1080 combinationsThat makes a total of 2550 combinations. This scheme does not differentiate between {13, 24, 5} and {1, 2, 3, 4, 5}. Adjusting for that would complicate the calculation considerably and reduce the number of combinations.
There is no such ratio that applies for all single-digit and double-digit integers.