If one person can clean a house in 5 hours and the second person can clean the same house in 4 hours, how long would will it take to clean the house if they worked together?

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

What volume of a 0.0606 m solution of strontium bromide is needed to obtain 0.340 mol of the compound? question 42 options: a)5.61 l b) 3.4 l c) 600 ml d) 1 l e) 178 ml