What is the percent by volume of a solution formed by mixing 25ml of isopropanol with 45ml of water?

Supposing additive volumes:

(25 mL) / (25 mL + 45 mL) = 0.357 = 35.7% isopropanol by volume

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.