Bitcoin will not be $7500 in 2 years unless something happens that can speed up the process of adoption. we can not predict that part but it will still be adopted and more people will invest in it because it is the ONLY trusted cryptocurrency with no bullshit and no bug and no premine. that is why i predict a price around $2500 to $3000 in 2 years.

litecoin however is still small and an altcoin. it will rise as it is the only altcoin i know which has real usage and people are actually using it as a currency in very small scale. it is being developed and the developers are in fact good not just some random guy pushing useless code like 90% of the altcoins.
again it is hard to predict, i expect if litecoin activates SegWit it can literary go to the moon. as in rise up to $100 in a couple of months and if not it can still grow. in two years i expect at least $10-$50 specially because all other useless junk has disappeared by then.