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Two (or four) digits added together cannot equal 42. Two-digit numbers multiplied together cannot equal 82.
Since the first integer of the 3-digit numbers must be 2, the sum of the second and the third digits would be 13.Since the largest digit is 9, the 3-digit numbers could be 249, 294, 258, 285, 267, and 276.Thus, there are 6 integers between 200 and 300 whose sum of their digits is 15.
No two numbers that can be completely written down with digits can be added, subtracted, multiplied, or divided to equal PI. If they could be divided to equal PI, then PI would be a rational number. But it isn't.
Write them as decimals, and compare. If the first digit of two numbers is equal, compare the second digit; if the second digit is equal, compare the third digit, etc.