Question

In a number of two digits, unit's digit is twice the tens digit. If 36 be added to the number, the digits are reversed. The number is.

Answer 1

Answer:

48

Answer. Answer: If 36 be added to the number, the digits are reversed and the unit's digit is 2 times the ten's digit, then the number is option 48.

Answer 2

Answer:

Let the tens digit be x.

Hence, the units digit will be 2x

Number =10×(x)+(2x)=12x

When 36 is added to the number, the new number formed =12x+36

As the digits are reversed, we can also write the new number as 10×(2x)+x=21x

Hence,

12x+36=10×(2x)+x

⇒12x+36=21x

⇒21x−12x=36

⇒9x=36

⇒x=4

Hence, the original number =12x=12×4=48