Davie and horatio are riding their motorbikes on a scenic tour that is 80 miles long. davie rides at 20 miles per hour and leaves 90 minutes before horatio. how fast must horatio ride to finish at the same time as davie?

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.