Question

A number consists of two digits. The digits in the ten's place is 3 times the digit in the unit's place. If 54 is subtracted from the number the digits are reversed. The number is​

Answer 1

Let the digit at Tens place be x

The digit at unit place be y

The Number is 10x + y

ACCORDING TO THE QUESTION :-

x = 3y ... eq. 01

According to the second condition :

10x + y - 54 = 10y + x

=> 9x - 9y = 54

=> 9(x - y) = 9 × 6

=> x - y = 6 ... eq.02

Now we can solve the Equation 01 and 02 by substitution Method :-

x - y = 6

=> 3y - y = 6 [ from eq.01 , x = 3y ]

=> 2y = 6

=> y = 3

Now we can substitute the value of y in eq. 01 to get value of x

x = 3y

=> x = 3 × 3

=> x = 9

Hence the number is

Hence the number is 10x + y = 90 + 3 = 93 (ANS)

VERIFICATION

As given in the question if we subtract 54 from 93 the digits get reversed.

93 - 54 = 39

Hence our Answer is correct.