At a pet store, there are 30 aquariums. Of the 30, 20 have fresh water with
15 fish each. The other 10 aquariums
have salt water with 6 fish each. Which
equation could be used to find f, the
total number of fish at the pet store?

f = (20 × 15) + (10 × 6)

Explanation:

You are just find how many fish are salt water and how many freshwater and adding them together. The total number of aquariums is irrelevant in this case.

idk

step-by-step explanation:

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- niki minaj

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.