A two digit number is such that the product of its digits is 18. When 63 is subtracted from the number, the digits interchange their places. Find the number.

Asked by Topperlearning User | 26th Feb, 2014, 03:41: PM

Expert Answer:

Let unit place digit = x and ten's place digit =

Number = (1) (x) + (10) …(i)

Interchanged Number = 10x + 1

Given,

x2 + 180 - 63x - 10x2 - 18 =0

-9x2 - 63x + 162 = 0

x2 + 7x - 18 = 0

(x+9) (x-2) = 0 x = -9 or 2

x = 2(Rejecting x = -9 as digit is not -ve)

From (i), Number = x +

Answered by  | 26th Feb, 2014, 05:41: PM

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