Question

The sum of the digits of a 2-digit number is 9.
If the tens digit is half of the ones digit, find the
2-digit number.​

Answer 1

Step-by-step explanation:

Let the digit at tens place be x

Digit at ones place be 2x

A/q, x+2x = 9

3x = 9

x = 9/3 = 3

Original no. = 10x3+2x3 = 36

Answer 2

${ \sf{ \underline{Hey!}}}$

→ Let the numbers at ones and tens place be x and y respectively.

•°• Number - x + 10 y

Sum of digits → x + y = 9 .....................(1)

Also ,

The tens digit is half of the ones digit so

y = ½ x .................(2)

Plug in this value of y in eq. 1

$= > x + \dfrac{1}{2} x = 9 \\ \\ = > \frac{3}{2}x = 9 \\ \\ = > 3x = 18 \\ \\ \implies \: { \bold{x = 6}}$

Put the value of x in eq. (1) to obtain the value of y ,

Y = 9 - x

$\implies { \bold{y = 3}}$

Number formed → x + 10 y

=> 6 + 10(3)

= 36

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