In your marble collection, 4/7 of the marbles are blue and 4/21 of the marbles are red. how many times more blue marbles do you have than red marbles?

3 times.

Step-by-step explanation:

We begin by knowing that 4/7 is greater than 4/21. So you should know how many times there are more blue marbles than red marbles. That's,

Let X = number of times there are more blue marbles than red marbles

4/7 = X * 4/21

Isolating X,

X = 4/7 ÷ 4/21

That's,  

Then there are three times more blue marbles than red marbles.

It can be easily demonstrated, by substituting X in the original equation, or multiplying 3 by 4/21

4/7 = X * 4/21

4/7 = 3 * 4/21

4/7 = 12/21

4/7 = 12/3 / 21/3

4/7 = 4/7

Hope this helps!

1/20

Step-by-step explanation:

1/20 is the answer