Given the arithmetic progression
what is ?
My doctor gave me some pills with the following instructions:
"Take 12 pills on the first day, and then reduce the amount by 3 pills on each subsequent day until you don't have to take any."
When will be the first day that I don't have to take any pills?
Which of the following sequences is NOT an arithmetic progression?
The numbers of red circles in each group in the above diagram form an arithmetic progression. What is the common difference?
If the above numbers form an arithmetic progression, what is its common difference?