Someone help and please make sure it’s right :)

Find the greatest common factor of the followig monomials 21u^5v,3u^4v^6, and 3u^2v^5

At the county fair, the baxter family bought 6 hot dogs and 4 juice drinks for $12.90. the farley family bought 3 hot dogs and 4 juice drinks for $8.55. find the price of a hot dog and the price of a juice drink.

The taxi fare in gotham city is $2.40 for the first 1 2 12 mile and additional mileage charged at the rate $0.20 for each additional 0.1 mile. you plan to give the driver a $2 tip. how many miles can you ride for $10?