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 × 10b, where a = 8 and b = ___
.

The mass of a grain of pollen can be estimated and written in the form a × 10b, where a = 2 and b =
.

Based on the estimates, the mass of a dust particle is approximately
times larger than the mass of a grain of pollen.