In order for you to be able to profitably conduct an exchange, you need to study the dynamics of the ltc to usd rate. And when you see that the price suits you using the cryptocurrency exchange for exchange
You can use online exchangers to find the most favorable rate and exchange conditions for you. see here https://www.bestchange.com/litecoin-to-visa-mastercard-usd.html exchanger offers for ltc to usd. BestChange monitors exchange rates in several hundred reliable exchangers and equips you with all the information you need to select the best exchanger to transfer your money