Jenny and penny can eat a whole gallon of ice cream together in 2 hours. penny and lenny can eat a whole gallon of ice cream together in 3 hours. all three together can eat a whole gallon of ice cream together in 1 hour. how many hours would it take jenny to eat a whole gallon of ice cream all by herself?

J, P, and L can each eat ice cream at respective rates of in gallons of ice cream per hour (gal/hr).

We're given that

We want to find . Subtracting the second equation from the third gives

so J can eat 2 gallons of ice cream in 3 hours, or 2/3 of a gallon per hour, so that it would take her 3/2 hours, or 1.5 hours, to eat 1 gallon on her own.

the solution is 12x-6y