Problem: Sum of two natural numbers is 20. If one number is one-fourth of the other, then the difference between the two numbers is?

Solution:

To solve the problem, we can use the following steps:

1. Let's assume that one of the numbers is "x" and the other number is "y".
2. According to the problem statement, we know that the sum of the two numbers is 20. Therefore, we can write the following equation:

x + y = 20

3. We also know that one number is one-fourth of the other. Let's assume that "x" is one-fourth of "y". Therefore, we can write the following equation:

x = y/4

4. Now we can substitute the value of "x" from the second equation into the first equation:

(y/4) + y = 20

5. Simplifying the equation, we get:

5y/4 = 20

6. Solving for "y", we get:

y = 16

7. Now we can substitute the value of "y" back into the equation "x = y/4" to get:

x = 4

8. Therefore, the two numbers are 4 and 16.

9. Finally, we can find the difference between the two numbers by subtracting the smaller number from the larger number:

16 - 4 = 12

Therefore, the difference between the two numbers is 12.

12