Question

The tens digit of a two-digit number is twice the unit digit. If the digits are reversed, the new number is 36 less than the original number. Find the number

Answer 1

The number is 84

Explanation:

x = unit digit

10(2 x) + x = 10 x+ 2 x + 36

9 x = 36

x = 4 (4 is the unit digit,which is half of the tens digit,so the tens digit is 8)

Number is 84

The reverse of 84 is 48

48 is 36 less than 84

84 = 48 + 36

Answer 2

The original number is 84.

Explanation:

Let the number be xy.

Then x = 2y.

The numerical value of xy is 10x + y,

so 10y + x = 10x + y - 36.

9y - 9x = -36

y - x = -4

Substitute for x in the above equation:

y - 2y = -4

-y= -4

So y = 4

and x = 2y = 8.