The sum of the digits of a two digit number is 10. If 18 be subtracted...
Solution:
Let the number be xy, where x and y are the tens and units digits respectively.
Given, x + y = 10
Therefore, x = 10 - y
When 18 is subtracted from the number, we get (xy - 18)
According to the question, the digits in (xy - 18) are equal. Therefore, we can write:
x - 1 = y - 8
Substituting the value of x from the first equation, we get:
(10 - y) - 1 = y - 8
9 - y = y - 8
2y = 17
y = 8.5
But y is a digit, which means it must be a whole number. Therefore, there is no two-digit number whose digits add up to 10 and whose digits are equal when 18 is subtracted from it.
Hence, the answer is that there is no such number.
The sum of the digits of a two digit number is 10. If 18 be subtracted...
Let x = 10's digit of a two digit numberLet y = units digitLet z = the resulting equal digits:Write an equation for each statement::"the sum of a two digit number is 10."x + y = 10ory = (10-x):" if 18 be subtracted from it, the digits in the resulting number will be equal."10x + y - 18 = 10z + z10x + y = 11z + 18:Substitute (10-x) for y10x + (10-x) = 11z + 1810x - x = 11z + 18 - 109x = 11z + 8:The single digit integer values for x and z are limited to x=7 and z=5 in this equation:x = 7, y = 3, z = 5:The number is 73:Check in the statement:"if 18 be subtracted from it, the digits in the resulting number will be equal."73 - 18 = 55
To make sure you are not studying endlessly, EduRev has designed CA Foundation study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in CA Foundation.