Question

A number consists of two digits whose sum is 9. If 27 is subtracted from

the number the digits are reversed. Find the number.​

Answer 1

Answer is 63

Step-by-step explanation:

Let the number =ab=10a+b

Sum of digits =9

a+b=9

number −27=number with reversrd digits

10a+b−27=10b+a

9(a−b)=27

a−b=3

(a+b)+(a−b)=9+3⇒a=6,b=3

∴ Required number is 63

Answer 2

Answer:

Step-by-step explanation:

Let us assume, x and y are the two digits of the two-digit number

Therefore, the two-digit number = 10x + y and reversed number = 10y + x

Given:

x + y = 9 -------------1

also given:

10x + y - 27 = 10y + x

9x - 9y = 27

x - y = 3 --------------2

Adding equation 1 and equation 2

2x = 12

x = 6

Therefore, y = 9 - x = 9 - 6 = 3

The two-digit number = 10x + y = 10*6 + 3 = 63