Which theory involves the enactive, iconic, and symbolic processes?

Need will give 100 ! in no less than one hundred fifty words, explain why it is important for engineers to sketch designs and use them to clarify their designs to other people, giving at least three reasons.

Essay questions may also be referred to as a. talk questions c. hard questions b. explain questions d. think questions

Raul has one solution that is 20% acid by volume and one solution that is 50% acid by volume. he plans to mix together some of each solution to create 30 milliliters of a solution that is 40% acid by volume. how many milliliters of the 20% acid solution should raul use to create the 40% acid solution? can someone explain this to me? i know that the answer is 10 milliliters, but i don't know how to get it.