Question

sum of two digits of a 2-digit number is 12. If the digits are reversed the new number, so formed incresae by 36. Find the number
​

Answer 1

Solution:-

Let one place is y

and tenth place is x

we get

10x + y

Given

x + y = 12 .......(i)eq

When digit is reversed

10y + x

When it increases by 36

10x + y + 36

We can write as

10y + x = 10x + y + 36

10y -y + x - 10x =36

9y - 9x = 36

9(y - x) = 36

y - x = 4 .........(i)eq

Using elimination method

add (i) with (ii)

x + y + y - x = 4 + 12

2y = 16

y = 8

Now put on ( i) eq

x + y = 12

x + 8 = 12

x = 12 - 8

x = 4

Number is 10x + y

10 × 4 + 8

40 + 8

=> 48

Answer 2

I have answered the question in the below pic