To find the approximate weight of all the ants in the world, you can multiply the average weight of an ant by the total number of ants.
- The weight of one ant is \( 3 \times 10^{-6} \) kg.
- The total number of ants is \( 1 \times 10^{16} \).
The total weight \( W \) of all the ants can be calculated as follows:
\[ W = (3 \times 10^{-6} , \text{kg}) \times (1 \times 10^{16}) \]
Now, we can multiply the coefficients and add the exponents:
\[ W = 3 \times 1 \times 10^{-6 + 16} \] \[ W = 3 \times 10^{10} \]
Thus, the approximate weight of all the ants in the world is \( 3 \times 10^{10} \) kg.