Four light bulbs cost $3.20.how much does it cost to buy 14 light bulbs

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2

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.

A6 ounce bottle of dressing costs $1.56 a 14 ounce bottle costs $3.36 a 20 ounce bottle costs $5.60 which has the lowest cost per ounce