1 3/20 is the answer. I turned both mixed numbers into a fraction. 15 1/4 into 61/4 16 2/5 into 82/5 I multiplied both the top and the bottom of 61/4 by 5 and got 305/20 I multiples both the top and the bottom of 82/5 by 4 and got 328/20 I subtracted these two and got 23/20 or 1 3/20