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A three digit number is equal to 17 times the sum of its digits; If the digits are reversed, the new number is 198 more than the old number ; also the sum of extreme digits is less than the middle digit by unity. Find the original number. |
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Answer» Let the digit in hundreds place be x and that in unit place be y. ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ H ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀x T ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀x + y + 1 unit⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀y ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
= 100x + 10x + 10y + 10 + y = 110x + 11Y + 10 the SUM of the digits in the given number = x + (x + y + 1) + y = 2x + 2y + 1 From first condition Given number = 17 ´ (sum of the digits)
The number obtained by reversing the digits = 100Y + 10(x + y + 1) + x = 110y + 11x + 10 Given number = 110x + 11y + 10 From 2nd condition, Given number + 198 = new number. 110x + 11y + 10 + 198 = 110y + 11x + 10 99x - 99y = -198
Substitute this value of x in equation (I).
Substitute this value in equation (II)
the digit in ten’s place is 3 + 1 + 1 = 5
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