Question

The sum of the digit of 2 digit number is 7 . if the digit are reversed, the new number increased by 3 less than 4 times of the original numnumber. find the number

Answer 1

Hi...☺

Here is your answer...✌

Let the ten's digit of number be x
and the unit's digit of number be y

Then,
Number = 10x + y
Reversed number = 10y + x

Now, According to the question

x + y = 7

y = 7 - x -----(1)

And,

10y + x = 4(10x + y) - 3

10y + x = 40x + 4y - 3

10y - 4y + x - 40x = -3

6y - 39x = -3

6(7-x) - 39x = -3 ___[ from (1) ]

42 - 6x - 39x = -3

- 45x = - 3 - 42

-45x = -45

=> x = 1

Putting x = 1 in eq(1), we get

y = 7 - 1

=> y = 6

=> Number = 10x + y = 10×1 + 6 = 16

HENCE,

The required number is 16