A number consists of two digits. The sum of the digits is 9. If 63 is subtracted from the number, its digits are interchanged. Find the number.
Choose the correct choice from the following answers.
A) 81	B) 90	C) 100	D) 61	E) 73
Let the ten's digit be x. Then, unit's digit = (9 - x).   Number = l0x + (9 - x) = 9x + 9.   Number obtained by reversing the digits = 10 (9 - x) + x = 90 - 9x.   therefore, (9x + 9) - 63 = 90 - 9x =&gt; 18x = 144 =&gt; x = 8.   So, ten's digit = 8 and unit's digit = 1.   Hence, the required number is 81.   81nswer 81)81.
<result>A</result>
A number consists of two digits. The sum of the digits is 9. If 63 is subtracted from the number, its digits are interchanged. Find the number.