15 gallons to 18 gallons express each ratio as a fraction in the simplest form

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

What is the perimeter of an isosceles triangle with each leg measuring 2x+3 and the base measuring 6x-2?

Acertain group of women has a 0.640.64% rate of red/green color blindness. if a woman is randomly selected, what is the probability that she does not have red/green color blindness? what is the probability that the woman selected does not have red/green color blindness? nothing (type an integer or a decimal. do not round.)