Question

6. 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

Answer:

36

Step-by-step explanation:

Answer 2

AnswEr

The required two digit number is 36

GivEn

• The sum of the digits of a two digit number is 9
• The digit on the tenth place is half of the digit at ones place.

SoluTion

Let the digits of the two digit number be x and y respectively

Therefore , the two digit number will be

$\tt \dashrightarrow 10x + y$

According to question

$\tt x + y = 9 \longrightarrow(1)$

Again by question

$\tt x = \dfrac{1}{2} y \longrightarrow(2)$

Putting the value of (2) in (1) ,

$\tt\implies \dfrac{1}{2} y + y = 9 \\ \\ \tt \implies \dfrac{y + 2y}{2} = 9 \\ \\ \implies \tt3y = 2 \times 9 \\ \\ \implies \tt y = 2 \times 3 \\ \\ \tt \implies y = 6$

Now putting the value of y in (2),

$\tt \implies \: x = \dfrac{1}{2} \times 6 \\ \\ \tt \implies x = 3$

Thus , the required number is

$\dashrightarrow \tt10 \times 3 + 6 \\ \\ \dashrightarrow \tt30 + 6 \\ \\ { \tt\dashrightarrow36 }$