Convert 5 2/5 into an improper fraction

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

Yesterday, george drank 1 small bottle and 2 large bottles, for a total of 1,372 grams. the day before , he drank 1 small bottle and 1 large bottle, for the total of 858 grams. how many grams does each bottle hold?

Yvaries inversely as x. y =12 when x=5. find y when x=4