Question

The sum of the digits of a two digit number is 5. The number formed by reversing the digits
is 9 less than the original number. Find the original no.
​

Answer 1

Answer:

34

Step-by-step explanation:

Let the digits be x and y

No. = 10x + y

x + y = 5..................1)

10x + y = 9 + 10y + x

9x - 9y = 9

Dividing 9 on both sides

x - y = 1.......................2)

1) + 2):

2x = 6

So, x = 3, and y =5 - 3 = 2

Original No. = 32

Answer 2

Given :-

• The sum of the digits of a two digit number is 5 the number formed by reversing the digits is 9 less than the original number

To Find :-

• Find the original number

Solution :-

• Let unit's digit be x
• Ten's digit be y

➞ 10 (5x - x) + x

➞ 50x - 10x + x

➞ 50x - 9x

After interchanging the number,

• Unit's digit = 5 - x
• Ten's digit = x

New number = 9x + 5

According to Question,

➞ 9x + 5 + 9 = 50 - 9x

➞ 9x + 9x = 50 - 14

➞ 18x = 36

➞ x = 36/18

➞ x = 2

✦ Unit's digit = 2

✦ Ten's digit = 5 - 2 = 3

Hence,

• The original number is 32.

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