5 1/4 divided by 7/20

15 0/1
In 5 1/4, multiply the whole number 5 by the denominator of the fraction 4 to get 20. This shows that the whole number represents 20/4
To find the numerator when an improper fraction use addition.
20/4 + 1/4 = 21/4
Flip 7/20 by swapping the numerator and the denominator to 20/7.
Multiply the numerators then multiply the denominators. 21/4 X 20/7 = 420/28.
Simplify fraction 420/28 by dividing out the greatest common factor which is 28 from the numerator and denominator. 420/28 = 15/1. 
Divide the numerator 15 by the denominator 1 to get 15 with remainder 0. The remainder is the new numerator 15 0/1 is the answer to the mixed number.