Can someone me i don’t understand how to set it up and to solve

What is the molecular formula for a compound that is 46.16% carbon, 5.16% hydrogen, and 48.68% fluorine? the molar mass of the compound is 156.12 g/mol

Measurements that have similar values are: a. usually accurate b. sometimes accurate c. always accurate d. never accurate

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.