At the start of the dry season, Yafiah's 3000 L water tank is full. She uses 183 L of water each week to water her garden.
a. Find the amount of water left in the tank after 1, 2, 3, and 4 weeks.
b. Explain why the amount of water left in the tank after n weeks forms an arithmetic sequence.
c. When will Yafiah's tank run out of water?