It would be amazing if you can help me with this!

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

What are the constants in this expression? -10.6+9/10+2/5m-2.4n+3m

An empty bucket is placed under a faucet dripping at a constant rate of 4 milliliters per minute. with the given information, which of these statements is a reasonable conclusion? a there will be 24 milliliters of water in the bucket after 16 hour. b there will be 60 milliliters of water in the bucket after 14 hour. c there will be 160 milliliters of water in the bucket after 20 minutes. d there will be 100 milliliters of water in the bucket after 40 minutes.