Question

A number consists of two digits whose sum is 8. If 18 is added to the number its digits are reversed. Find the number ​

Answer 1

Answer:

• Original no. = 53
• Reversed no. = 35

Step-by-step explanation:

• Let the tens digit be x and ones digit be y

x + y = 8 .........i

10x + y + 18 = 10y + x

10x - x + y - 10y = 18

9x - 9y = 18

9 (x - y = 2)

x - y = 2......ii

• Now, we solve eq i and ii simultaneously

       x + y = 8

+      x - y  = 2      

      2x = 10                                             (+y -y get cancelled)

       x = $\frac{10}{2}$

       x = 5

• Substituting the value of x in eq i

x + y = 8

5 + y = 8

y = 8 - 5

y = 3

• Therefore, original no. = 53 and reversed no. = 35 and 53 - 18 = 35

Answer 2

Answer:

The answer is 35.

Step-by-step explanation:

Let one of the digit of two digit no. be x .

then other no. is (8 - x )

so, we get equation

10x + ( 8 - x ) + 18 = 10 ( 8 - x ) + x

10x + 8 - x + 18 = 80 - 10x + x

9x + 26 = 80 - 26

18x = 54

x = 54/18

x = 3

The digit in tens place is 3

The digit in ones place is 8 - 3 = 5

therefore, no. is 35.

Now

According to question 18 is added to digit

then it become reversed i.e. 53.

So final answer is 35.