Question

the sum of the digits of a two-digit number is 6 if its digit were reversed the new number so formed is decreased by 18 the number is​

Answer 1

Step-by-step explanation:

a+b=6⟹b=6−a

10b+a=10a+b−18

⟹9b=9a−18

⟹6−a=a−2

⟹2a=8

a=4⟹b=2

Thus the number is 42.

Answer 2

Answer:

The required number is 42.

Step-by-step explanation:

Let the tens digit be x and units digit be y.

The, the number = 10x + y

The sum of the digits of the two-digit number is 6.

 x + y = 6

⇒ x = 6 - y

If the digits are reversed, the number formed is 10y + x

According to the question,

10y + x = 10x + y - 18

10y - y = 10x - x - 18

 9y = 9x - 18

  9y = 9(x - 2)

  y = x - 2

Substitute x = 6 - y,

y = 6 - y - 2

y + y = 4

2y = 4

  y = 4/2

  y = 2

Therefore, the units digit is 2.

⇒ x = 6 - y

⇒ x = 6 - 2

⇒ x = 4

The tens digit is 4.

The number = 10(4) + 2 = 42