There are 16 coins totaling $1.08. All 16 coins were pennies, nickels, and dimes. The number of dimes is equal to the sum of the number of pennies and the number of nickels. How many of each coin is there?

Let the number of nickels be x

Let the number of pennies be y

Let the number of dimes be z

Now z=x+y

FIrst equation:

z+x+y=16

Subsittue for z:

x+y+x+y=16

y=8-x (subsitution)

Hope this helps :)

Step-by-step explanation:

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.