Answer:
6.5 × 10^9 kg
Explanation:
Here is the answer to the question the way it is asked, but the question is ridiculous. 1 kernel of popcorn has a mass of perhaps 1.5 g, so 1.25 g is reasonable. That means 1 kernel has a mass of 0.00125 kg, or 1.25 × 10^-3 kg. To state that 1 kernel of popcorn has a mass of 1.25 × 10^1 means that a kernel of popcorn has a mass of 12.5 kg which corresponds to a weight of approximately 27.6 lb. That is just ridiculous.
Using the ridiculous information given in the problem, then if 1 kernel has a mass of 1.25 × 10^1 kg, then 5.2 × 10^8 kernels have a mass of
(1.25 × 10^1 kg) × (5.2 × 10^8) =
= (1.25 × 5.2) × (10^1 × 10^8) kg
= 6.5 × 10^9 kg
Your number is correct, but don't forget the units.