Question

In a two-digit number, the digit at the unit place is double the digit in the tens place. The number exceeds the sum of its digits by 18. Find the number.

Answer 1

Our first given condition is that the digit at the unit place is double the digit in the tens place. 

∴ Let the tens digit be y. 

The digit in the units place is 2y. 

Number = 10y + 2y = 12y 

Now the second condition is that the number exceeds the sum of its digits by 18. 

∴ By given condition, 

(y + 2y) + 18 = (10y + 2y) 

∴ 3y + 18 = 12y 

12y - 3y = 18 

9y =18 

∴ y = 2 

Hence, the digit in the tens place is 2. 

So, digit in the units place is 4. 

∴ Our number is 24.