Answer:
3/8
Explanation:
convert mixed numbers to improper fractions
21/4 = 9/4
convert element to fraction
6=6/1
9/4 divided by 6/1
apply the fraction rule (hope you're familiar)
9/4 * 1/6
cross- cancel common factor 3
3*1 = 3
4*2 = 8
multiply the numbers
3/ 4*2
3/8