I would think the last one about the ozone layer
If the cyclist rode at an average speed of 10mph for 15 miles...
we can solve by dividing the distance by the speed to get time using the equation...
Δspeed = Δdistance / Δtime
Δtime = Δdistance / Δspeed
Δtime = 15 miles / 10 mph = 1.5 hours
Answer:
Sulfur hexafluoride, also known as sulfur(VI) fluoride, is a chemical compound. Its chemical formula is SF6. It contains sulfur in its +6 oxidation state.
I am not to sure because I have not studied this