Petrolyn motor oil is a combination of natural oil and synthetic oil. it contains
7 liters of natural oil for every 4 liters of synthetic oil. in order to make
792liters of petrolyn oil, how many liters of natural oil are needed?

When you answer this can you explain

Janie has $3. she earns $1.20 for each chore she does and can do fractions of chores. she wants to earn enough money to buy a cd for $13.50. write an inequality to determine the number of chores, c, janie could do to have enough money to buy the cd.

(60 points) explain this in detail