Question

In a two-digit number, the digit in the units place is twice the digit in the tens place. If 27 is added to
it, digits are reversed. Find the number.​

Answer 1

Answer:

Solution-

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

Number = 10y + x.

If we reverse the digits, New number = 10x + y (y will be on tens digit and x will be on unit digit).

According to the question,

First condition -

→y = 2x

→ 2x - y = 0..(1)

Second condition -

→ (10+x)−(10x+y) = 27

→ 10y + x - 10x - y = 27

→ 9y - 9x = 27

→ 9(y - x) = 27

→ y - x = 27/3

→ y - x = 3

→ y = 3 + x..(2)

Put the value (2) in (1).

→ 2x - (3 + x) = 0

→ 2x - 3 - x = 0

→ x - 3 = 0

→ x = 3

Now, put x = 3 in (2).

→ y = 3 + 3

→ y = 6

Number = 10x + y

→ Number = 10 (3) + 6

→ Number = 30 + 6

→ Number = 36

Hence, required number is 36.

Answer 2

Step-by-step explanation:

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Question:

In a two-digit number, the digit in the units place is twice the digit in the tens place. If 27 is added to it, digits are reversed. Find the number.

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SOLUTION :

Its a 2 digit number.

Let one digit be x and other y.

So number is 10x+y.

When reversed it is 10y+x

Subtracting the original number from reversed we have 9(y-x) which is 27.

So y-x is 3 (divide both sides by 9).

Now y is units digit.

So y is 2x..

Substituting y with 2x in above equation we have X= 3

So y is 2x or 6.

So the number becomes 36.

Hence the number is 36.