Question

4. The sum of the digits of a two-digit number 15
The number obtained by interchanging the digits
exceeds the given number by 9. Find the number.
5. A two-digit number is such that the product of its​

Answer 1

Answer:

the answer is 87.......................

Answer 2

Answer:

= 78  

Step-by-step explanation:

Given:-

Let the tens and the units digits of the required number be x and y, respectively.

Required number = (10x + y)

To Find:-

The number.

Solution:-  

ATQ, We have

x + y = 15 ……..(i)  

Number obtained on reversing its digits = (10y + x)  

∴ (10y + x) = (10x + y) + 9  

⇒ 10y + x – 10x – y = 9  

⇒ 9y – 9x = 9  

⇒ y – x = 1 …….(ii)  

On adding Eq (i) and (ii), we get:  

2y = 16  

⇒ y = 8  

On substituting y = 8 in (i), we get:  

x + 8 = 15  

⇒ x = (15 – 8) = 7  

Number = (10x + y) = 10 × 7 + 8 = 70 + 8 = 78  

Hence, the required number is 78.