To do this, you can just multiply across. 3 times 1 equals 3 so your numerator is 3. 2 times 4 equals 8. Then, your answer would be 3/8. Hope this helps :)
The formula for circumference = 2*Pi*r
R= radius. Radius is half of the diameter, and d= 20. This means that radius = 10. Now we have a full formula to work with.2*Pi*10.
Substitute 3.14 for pi.
3.14 * 10 = 31.4.
31.4*2 = 62.8.
62.8 rounded equals 63.
C = 63.
r > 0 = r is greater than 0
r ≤ 8 = r is less than and equal to 8
0 ≤ r ≤ 8
Answer:
25
Explanation:
In order to solve this the easiest way you can use equivalent fractions.

Since 4 times 5 equals 20 we can multiply 5 times 5 to get our answer.

25 is the answer. But, if we couldn't have gotten to 20 through the multiplication we could use a proportion. That would look like the initial problem but instead of a "?" we would use a variable. I will use <em>t</em> for total.

So now we have our problem set up. The next step is to cross multiply. 4 by <em>t</em> and 5 by 20.

And now we can solve it like a normal algebra problem.

Either way, we get 25.
For the first marble would be: 2/11
For the second: 3/11