Answer:
I think section #3
Explanation:
When i was in science class in my memory it was always in that area
Additive color mixing involves multiple sources of light with different colors in each source. Subtractive color mixing involves a single source of light with different colors absorbing various wavelengths of the color spectrum. Secondary colors of one system serve as the primary colors for the other.
Solve these problems like weighted averages:
The first one:
Multiply the masses (isotope numbers) by the decimal form of the percentage. Add them
0.076 (6) + 0.924 (7) = 6.924
The second one:
0.2 (10) + 0.8 (11) = 10.8
If you think about it, these answers make sense. 6.924 is much closer to 7 than to 6 (since there's a lot more lithium-7 than there is lithium-6). 10.8 is closer to 11 than to 10.
