Anita and Ruth like to ride their bikes on the weekend. Ruth figures that if they would just increase their average speed by 1.25
km per hour, they can ride at least as far in 3 hours as it now takes
them 3.5 hours.
What is their current best average speed?

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.