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The sum of all three-digit numbers less than or equal to 500, that are formed without using the digit 1 and they all are multiple of 11 is |
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Answer» Such numbers are 11 x 19, 11 x 20, 11 x 22, 11 x 23,....., 11 x 28, 11 x 30, 11 x 32,....., 11 x 37, 11 x 39, 11 x 40, 11 x 42,.....,11 x 45 Sum = 11 (19 + ..... + 45 - 21 - 29 - 31 - 38 - 41) = 11 (1 + ..... + 45 - 160 - (1 + 2 + 3 + ..... + 18)) = 11 (1035 - 160 - 171) = 11 x 704 = 7744 |
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