Answer: 
Step-by-step explanation:
First, we need to find the common denominator
The easiest way to do this is by multiplying the two given denominators, which are 2 and 5.
2 × 5 = 10
So, our common denominator is 10. Then, multiply the numerators of the two fractions by 2 and 5. Here's why:
= 
We multiplied the top and bottom by 2 to make sure our new fraction stays equivalent to the original fraction.
Do the same thing for the other one:
= 
Finally, subtract the two fractions to find the difference between the two times:
=
The reason we used the common denominator is because we can only add or subtract fractions if they have the same denominator.
Answer:
A. principal interviewed the 25 students who scored highest on a reading test.
D. For a report on the exercise habits of adults, Sergio talked to 30 adults at a local fitness center.
E. Josh asked the first 25 people he met at the dog park if they preferred dogs or cats.
Step-by-step explanation:
Biased means if the selection of every unit does not have an equal chance of being selected in a sample.
The sample is said to be good if choosing the unit is unbiased. The sample is said to be unbiased if the selection of each unit is independent.
Option A is an example of data selected in a biased way because principal chose only those student who scored the highest marks on reading test.
Options B and C are unbiased as here a selection of each number and name of the student has an equal chance of being selected.
Option D is biased because Sergio talked adults at a local fitness center where people go for maintaining their health. So, there is a chance of the selection of fitted adults more than unfitted adults.
Option E is biased because Josh met people at the dog park where dog lovers are more than a cat lover.
Answer:
a.
Step-by-step explanation:
girls 60/50
boys 40/50
40/50 is 10
see the attached figure to better understand the problem
we know that
The point G is where all medians intersect and is often described as the triangle's center of gravity or centroid. It is formed by the intersection of the medians. The centroid divides each median in a ratio of 
so
<u>Find the value of FA</u>
therefore
<u>the answer is
</u>
