Write the following proportion using colons. 7 is to 21 as 3 is to 9.

I believe its the first option (pick 3 times, roll a 2, pick and replace 5 marbles, pick a red marble)

Step-by-step explanation:

The number of days (70) does not matter because you’re not looking for the number of times they ran, you’re looking for the chances that they run on a Tuesday. On a di, the equivalent of 1/3 is 2/6 so every time you roll a 2, it is 1/3 of the time. Finally, he goes to school 5 days of the week and Tuesday is only 1 day so pick one color (red) for every Tuesday.