One mole of an unknown sample contains 120 g of carbon and 30.3 g of hydrogen. what is the empirical formula of the compound?

List out the elements present in the compound, that is, Carbon and Hydrogen.
                 Carbon    (C)                                               Hydrogen (H)
divide by     120/12 =                                                            30.3 /1 =
the RAM         10                                                                  30.3

divide by        10/10                                                              30.3/10 =
smallest            1                                                                        3.03  
answer

do the ratio               1                                 :                                    3 (approximately)

Empirical formula = CH3

                  

Question was not very clear if there are specific answer choices tell me and i'll try to you more. hope this though2 laps is 1 min. we know that for each min she does two times the amount of laps. for 12 laps we can do 12/2 which does give us 12 laps in 6 mins not 16 mins.