James found a puppy today . now he has 4 more puppies than his sister cara .(1) write an expression to represent the number of puppies james has .let c represent the number of puppies cara has (2)write an expression to represent the number of puppies cara has . let j represent the number of puppies james has .(3)if james has 7 ppuppie how many does cara have ?

20 hour

Step-by-step explanation:

Let the total capacity of the pool is 100%

It is given that 2/3 of the pool is already filled means % is already filled

So 100%-66.66%= 33.33 % pipe is empty

it is given that it takes 12 hours to fill the pool so inlet rate is

It is also given that it can empty in 15 hours so outlet rate is So equivalent rate for filling the pool is %

So time required to fill the pool is hour