Provide me a handwritten solution and not an ai generated response.

Q$.1000$ electric bulbs are required per year. The ordering cost for these is Rs$.100$ per order and the carrying cost is assumed to be $40\%$ of the per unit cost. In orders of less than $120,$ drills cost Rs$.78$; for orders of $120$ or more, the cost drops to Rs$.50$ per unit. Should we take advantege of the quantity discount?