According to today's market estimate, the current price of LTC is: $64.03, the Antminer L3+ (504Mh) can mine 0.00223368 LTC every 24 hours, if the electricity cost is 6 cents/kwH, you can make profit per year.
Of course, if you calculate the net profit, you also need to deduct the cost of purchasing the mining machine.
If you choose to host the miner, you will also need to deduct the hosting fee.