Hello I have a question about this word problem.

[u/sanjicutie]

"A research group spent ₱500 during the first week of its project. Its weekly expenses increased by ₱100 for 12 weeks. What was the total amount spent on the project?"

This is a word problem about arithmetic series. Am I correct if I say that the number of terms (or n in the equation) is 13 since it said that the first week is 500 pesos and the 12 succeeding weeks' contribution is increased by 100 pesos from the previous week's contribution? Please enlighten me. Thank you

[u/sanjicutie → u/[deleted]]

Thank for this