Dan has a total of 12 bill in his wallet.
some are $5 bills and the rest are $10 bills.
the total value of the 12 bills is $115.
how many $5 bills and how many $10 bills does he have?

Anut store normally sells cashews for? $4.00 per pound and peanuts for? $1.50 per pound. but at the end of the month the peanuts had not sold? well, so, in order to sell 40 pounds of? peanuts, the manager decided to mix the 40 pounds of peanuts with some cashews and sell the mixture for $2.00 per pound. how many pounds of cashews should be mixed with the peanuts to ensure no change in the? profit?