Question

The sum of two digits is 10. If the places of the digits are changed then the
new number is decreased by 18. Find the number​

Answer 1

Answer:

64

Step-by-step explanation:

Let the unit digit be x

&

The tens digit be y

So

The 2 digit number formed = 10y + x

We the digits are changed the new number is decreased by 18

=> (10y + x) - (10x + y) = 18

=> 10y - y + x - 10x = 18

= 9y - 9x = 18

= 9(y - x) = 18

= y - x= 18/9 = 2..... (i)

&

Given that x + y = 10.... (ii)

From eq(i) y - x= 2 => y = 2 + x

Putting this value of x in eq (ii) we get

X + y = 10

= x + 2 + x = 10

= 2x = 10 - 2

= x = 8/2 = 4

So y = 2 + x = 2 + 4 = 6

So the number is 10y + x = 6×10 + 4 = 64