Question

digit in unit's place is twice that of the number in ten's place. if 27 is added to the the number digits arw revesed. find the number​

Answer 1

Answer:

Given :-

In a two digit number digit in units place is twice the digit in the tens place.

If 27 is added to its digits are reversed.

Solution :-

Let ten's digit = x

Unit's digit = 2x

Required Number = 10x + 2x = 12x

On Interchanging the Digit's Number = 10 (2x) + x = 21x

According to The Question

⇒ 12x + 27 = 21x

⇒ 27 = 21x - 12x

⇒ 27 = 9x

⇒ 27/9 = x

⇒ 3 = x

Required Number = 12 × 3 = 36

Hence, the number required number is 36.

Answer 2

Answer:

36

Step-by-step explanation:

let the number be xy with y in unit's place and x in tens place.

remember that any two digit number say xy can be written as 10x+y.For example 56=5×10+6

GIVEN,

digit in unit's place is twice that of ten's place.

y=2x ----- equation 1

if 27 is added digits are reversed (xy becomes yx in the sense how 12 changes to 21)

so 27+xy=yx

27+10x+y=10y+x

27+10x-x=10y-y

27+9x = 9y

27 = 9y-9x

27 = 9(y-x)

27/9=y-x

3 = y-x

{ from equation 1 ; substitute y as 2x }

3= 2x-x

x=3 and y= 2(3)=6

so the original number is 36.