Question

a number consists of two digits whose sum is 9. if 27 is subtracted from the number it's digits are reversed. find the number.
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Answer 1

Answer:

Step 1 :Let the unit’s digit be x

Step 2 :Then, ten’s digit = (9 – x)

∴ Number = 10 × (9 – x) + x

⇒ 90 – 10x + x = (90 – 9x)

Step 3 :Adding 27 to the number 90 – 9x, we get 117 – 9x

Step 4 :Number with digits interchanged is 10x + (9 – x) = 9x + 9

Step 5 :117 – 9x = 9x + 9

Step 6 :Therefore unit’s digit = 6 and ten’s digit = 3

Step 7 :Hence the number = 36.

Step-by-step explanation:

UR ANS

Answer 2

Answer:

36 or 63 can be the number

Step-by-step explanation:

Assuming

x as tens digit

y as ones digit

Their sum :

x + y = 9 ..... (i)

Number formed :

10x + y

Interchanging the digits :

10y + x

According to the question :

➡ (10x + y) - (10y + x) = 27

➡ 9x - 9y = 27

➡ 9(x - y) = 27

➡ x - y = 27/9

➡ x - y = 3 ..... (ii)

Subtracting both the equation :

$\bf \: x + y = 9 \\ { \underline{ \bf{x - y = 3}}} \\ \implies \bf \: 2x = 6 \\ \implies \bf \: x = 3$

Substituting the value of x in equation (i) :

➡ x + y = 9

➡ 3 + y = 9

➡ y = 6

Hence

The number can be 10x + y

or, 10(3) + 6

or, 36 either 63