How many litres of water will have to be added to 1125 litres of the 45% solution of acid so that the resulting mixture will contain more than 25% but less than 30% acid content?

A manufacture has 600 litres of a 12% solution of acid .How many litres of a 30% acid solution must be added to it so that acid content in the resulting mixture will be more than 15% but less than 18% ?

The following will have pH more than 7 or less than 7? Acid rain.

A solution of 8% boric acid is to be diluted by adding a 2% boric acid solution to it. The resulting mixture is to be more than 4% but less than 6% boric acid. If we have 640 litres of the 8% solution, how many litres of the 2% solution will have to be added?

How many times must a man toss a fair coin so that the probability of having at least one head is more than 90%?

How many times must a man toss a fair coin so that the probability of getting at least one head is more than 90%?

How many times must a man toss a fair coin so that the probability of getting at least one head is more than 90%?

How many times must a fair coin be tossed so that the probability of getting at least one head is more than 80%?