Question

officials begin to release water from a man made lake at a rate that would empty the lake in 16 weeks, but a river that can fill the lake in 30 weeks is replenishing the lake at the same time. how many weeks does it take to empty the lake? express you answer as a fraction reduced to the lowest terms, if needed.​

Answer 1

Answer:

34²/7

Step-by-step explanation:

Take the dam to be a take and the exit of the dam to be a tap at the bottom which is used to empty the tank and the river to be a pipe at the top of the tank that is used to fill the tank

The tap takes 16 week to empty the tank how much will it empty in 1 week =¹/16

The pipe takes 30 week to fill the tank how much will it fill in 1 week =¹/30

¹/16-¹/30= ?

Get the LCM of the denominator which is 240

The fractions are now

15/240-⁸/240=⁷/240

1week=⁷/240 empty

? = 240/240 empty

Cross multiple

240/240×1÷7/240

240/240×1÷240/7=240/7

7÷240=34²/7 weeks