There are 9 × 10^5 grains of rice in the container.
Step-by-step explanation:
Mass of empty container = 0.6 kg
Mass of container filled with rice = 18.6 kg
⇒ Mass of rice = 18.6 - 0.6 = 18 kg
Mass of one grain of rice = 2 × 10^-2 g = 2 × 10^-2/10³ kg (∵ 1 kg = 1000 g)
= 2 × 10^-5 kg
⇒ Number of grains of rice = Total Mass of rice/Mass of 1 grain
= 18/2 × 10^-5
= 9 × 10^5 grains of rice