Question 9: 1/3÷3
Answer: 1/9
Picture a pie and and having 1 slice out of the total 3 pieces, which would be 1/3 of the pie. Now, we want to divide the the pie into 3 more equal-piece groups. This means every original piece of the pie would now have 3 slices in each piece, so the pie would have a total of 9 pieces now. We want to keep our original 1 slice of pie, but now we have taken 1/9 of the pie, a much smaller slice.
What we have done is simply multiplied the denominator (bottom number of the fraction) by 3. In other words, the number of total pieces of pie is tripled from 3 to 9, meaning more slices would have to be cut, but the amount of pie stays the same. We are just taking a smaller slice. This is why the rule for dividing fractions is Keep Change Flip, because we really just want to the denominator to multiply.
Question 10: 1/4÷5
Answer: 1/20
The same logic applies.