A used bookstore sells hardback books and paperback books. A hardback book costs $11, including tax. A paperback book costs $5, including tax. Jamal bought 3 more paperback books than hardback books. Jamal spent $47. How many paperback books did Jamal buy?

5 paperback books

Step-by-step explanation:

From the question:

A used bookstore sells hardback books and paperback books. A hardback book costs $11, including tax. A paperback book costs $5, including tax. Jamal spent $47.

Let the number of paper backs = p

Let the number rod hardbacks = h

Hence:

$11 × h + $5 × p = $47

11h + 5p = 47

Jamal bought 3 more paperback books than hardback books.

h + 3 = p

h = p - 3

How many paperback books did Jamal buy?

Hence:

11h + 5p = 47

11(p - 3) + 5p = 47

11p - 33 + 5p = 47

16p = 47 + 33

16p = 80

p = 80/16

p = 5

Hence, he bought 5 paper back books

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.

answer: 140

step-by-step explanation:

so just add all then it will be your answer but i am not pretty sur eif it is but hope this i am here to people