Question

A two-digit number is obtained by either multiplying the sum of the digits by 8 andthen subtracting 5 or by multiplying the difference of the digits by 16 and thenadding 3. Find the number.

Answer 1

let the unit digit and the ten's digit of the number be x and y respectively.

therefore the number = 10y + x.

sum of digits = x+y

10y + x = 8(x+y) - 5

10y + x = 8x + 8y = - 5

7x - 2y = 5 -------- i)