Question

the ones digit of a two digit number is twice the tens digit. when the number formed by reversing the digits is added to the original number, the sum is 99. find out the original number

Answer 1

✌✌Hey, mate here is your answer⤵

Let, the tens digit =x
so, ones digit =2x
.•. number= 10x+2x=12x
reverse number= 10×2x+x=20x+x=21x

it is given that,
12x+21x=99
or 33x=99
so, x=3

original number=10x+2x
=30+6
=36 answer.

Hope this answer will help you..《《

Answer 2

Answer:

Let the tens digit be y and the ones digit be x.

The original number = 10y + x

The reverse number = 10x + y

It is given that ones digit is twice the tens digit :]

➳ x = 2y ............[Equation (i)]

According to question now,

➳ 10x + y + 10y + x = 99

➳ 11x + 11y = 99

➳ 11 (x + y) = 99

➳ x + y = 99/11

➳ x + y = 9

➳ y = 9 - x.........[Equation (ii)]

Now, Substituting equation (ii) in equation (i) we get :

➳ x = 2 (9 - x)

➳ x = 18 - 2x

➳ 3x = 18

➳ x = 18/3

➳ x = 6

Putting x = 6 in equation (ii) we get :

➳ y = 9 - x

➳ y = 9 - 6

➳ y = 3

Therefore,

The original number = 10y + x = 10(3) + 6 = 30 + 6 = 36