Answer:
a = 20
Step-by-step explanation:
The mean is calculated as
mean = 
= 
= 
Then
= 27 ( multiply both sides by 5 to clear the fraction )
115 + a = 135 ( subtract 115 from both sides )
a = 20
Divide the pages read by the portion read:
60/ 3/4 = 60 x 4/3 = 240/3 = 80
The book has 80 pages.
The answer choice which explains that the three segments cannot be used to construct a triangle is; AC + CB < AB.
<h3>Which inequality explains why the three segments cannot be used to construct a triangle?</h3>
Since, It follows from the triangle inequalities theorem that sum of the side lengths of any two sides of a triangle is greater than the length of the third side.
Hence, since the sum of sides AC + CB is less than AB, it follows that the required inequality is; AC + CB < AB.
Read more on triangle inequalities;
brainly.com/question/309896
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They mowed total of 11/15 (5/15 + 2/5) already, so they still have 4/15.
