Safe limit of water fluoride level is

There are 100 million litres of fluoridated water in the reservoir containing a city\'s water supply, and the water contains 700 kg of fluoride. To decrease the fluoride content, fresh water runs into the reservoir at the rate of 3 million litres per day, and the mixture of water and fluoride, kept uniform, runs-out of the reservoir at the same rate. How many kilograms of fluoride are in the reservoir 60 days after the pure water started to flow into the reservoir?

State the safe limit of sound level in terms of decibel for human hearing.

Tolerable limits of lead and fluorides drinking water according to international standard are respectively

Tolerable limits of lead and fluorides in drinking water according to international standard are respectively

The Tolerable limit of fluoride is ________ ppm.

What is the tolerable limit of fluoride ions in drinking water ? What happens if its exceeds 10 ppm ?

What should be the tolerable limit of fluoride ions in drinking water ? What happens if it is higher than 10 ppm.