Question
In a two digit positive number, the digit in the
unit’s place is equal to the square of the digit in ten’s place, and the difference between the number and the number obtained by interchanging the digits is 54. What is 60% of the original number?Solution
Let the number = 10x + x 2 According to the question, (10x2 + x) - (10x + x2) = 54 9(x2 - x) = 54 x2 - x = 6 x2 - x - 6 = 0 (x - 3) (x + 2) = 0 x = 3 or x = -2 Number = 39 [x `!=` 2] 60% of 39 = `60/100xx39` = 23.4
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