To find out how many gallons of perfume will be in each container, we need to divide the total amount of perfume by the number of containers.
First, let’s calculate the number of containers:
\[ 3.5 \times 10^2 = 3.5 \times 100 = 350 \text{ containers} \]
Now we can divide the total gallons of perfume by the number of containers:
\[ \text{Gallons per container} = \frac{10.5 \text{ gallons}}{350 \text{ containers}} \]
Calculating this gives:
\[ \text{Gallons per container} = \frac{10.5}{350} \]
This can be simplified step by step. First, perform the division:
\[ 10.5 \div 350 \approx 0.030 \]
Now we need to express this in scientific notation. The value \(0.030\) can be written as:
\[ 3.0 \times 10^{-2} \]
Thus, the amount of perfume in each container is:
\[ \boxed{3.0 \times 10^{-2}} \text{ gallons} \]