Answer
Part A: 14/100
Part B: 21/100
Part C: 30/100
Part D: 25/100
Work Step by Step
Part A: Seeing as all pie charts are out of 100%, it would be much easier to add up in later problems if you multiplied this times two seeing as your denominator is 50, which is how to get 14/100 from 7/50.
$(7/50)*2 = (14/100)$
Part B: For this one, one just has to find the section of the pie chart that is engineering and find the fraction labelled.
Part C: The question you have to make both denominators equal to one another. To make it easier to add in the end, try to make both denominators 100. So...
$(4/25)*4$ and $(7/50)*2$ would give you $(16/100)$ and $(14/100)$
Knowing that, you just add the two numerators together to give you $(30/100)$
Part D: This is where making all of your denominators 100 would help you. What you have to do is add all the known fractions together and subtract that by 100. However, you have to make sure all of your denominators are the same.
$(3/100) + (21/100) + (7/100)+ [(7/50) *2] + [(7/50)*2] + [(4/25)*4] = (75/100)$
$100-75= 25$ Answer: 25/100