Question

Frame an equation on the following: a two - digit number is 7 times the sum of its digits. (Assume two digit number as xy)

• A. x + y = 0
• B. x - y = 0
• C. x + 2y = 0
• D. x - 2y = 0

Answer 1

The correct option is D x - 2y = 0

Let the two-digit number be 'xy'
So, the representation of the two digit number is 10x + y.
$\therefore$ According to the question,
10x + y = 7 (x+y)
$\Rightarrow$ 3x = 6y
$\Rightarrow$ x - 2y = 0
Hence, required equation is x - 2y = 0