Her average in first three test = 89
This means, her total scores in first three test were = 3 x 89 = 267
Her average in four tests = 91
This means, her total scores in four tests are = 364
267 give the sum of first three test scores. and 364 give the sum of scores with fourth test adding in three tests.
So, subtracting 267 from 364 will give us the scores of Fourth test.
Scores of Fourth test = 364 - 267 = 97
Thus, Samantha's Claim is correct
BD=90 DF=110 meaning BF=200
200/5x
X=40
Answer:
C. √2 - 1
Step-by-step explanation:
If we draw a square from the center of the large circle to the center of one of the small circles, we can see that the sides of the square are equal to the radius of the small circle (see attached diagram)
Let r = the radius of the small circle
Using Pythagoras' Theorem 
(where a and b are the legs, and c is the hypotenuse, of a right triangle)
to find the diagonal of the square:



So the diagonal of the square = 
We are told that the radius of the large circle is 1:
⇒ Diagonal of square + r = 1





Using the quadratic formula to calculate r:




As distance is positive,
only
Answer:
sin 50°
Step-by-step explanation:

I am pretty sure it's 82/100.