The sum of the digits of a two − digit number is 11. The unit's digit is 7 less than the ten's digit. Find the number.

Number = 92

Step-by-step explanation:

Let the unit digit is x and that of tens digit is y.

ATQ,

x+y = 11 (1)

The unit's digit is 7 less than the ten's digit

x = y-7 ...(2)

Put the value of x from equation (2) in (1)

y-7+y = 11

2x-7 = 11

2x = 11+7

2x = 18

x = 9

Put the value of x in equation (1)

9+y = 11

y = 2

Hence, the number is 92.