The total age of two sisters is 108 years One is 18
years
older than the other. Find the
ratio of the age of the older to the
younger

7 : 5

Step-by-step explanation:

let the age of the younger be x , then the older is x + 18, thus

x + x + 18 = 108, that is

2x + 18 = 108 ( subtract 18 from both sides )

2x = 90 ( divide both sides by 2 )

x = 45

Thus younger is 45 and older is 45 + 18 = 63

ratio older : younger = 63 : 45 = 7 : 5

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.

35x 3= 105

step-by-step explanation:

35+35= 70   70 + 35= 105