In one year, a school uses 13,270 pieces of white paper, 6,570 fewer pieces of blue paper than white paper, and 2,600 fewer pieces of yellow paper than blue paper. How many pieces of paper does the school use in all?

24,070 the school uses in all

Step-by-step explanation:

You subtract 13,270 by 6,570 and you get 6,700 pieces of blue paper. Then, you subtract 6,700 by 2,600 and you get 4,100 pieces of yellow paper. Finally, you add the total of pieces of white, blue, and yellow paper and you get 24,070 for the total.

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.

what is the original number? you forgot to add it.