4% of the 200 pills failed to retain full potency after 60 days.
Answer:
25a-20
Step-by-step explanation:
15a+10a-20=
25a-20
Problem 37
<h3>Answer: B. 4 & 1/4 gallons</h3>
-------------------
Work Shown:
The 3/4 and 1/2 add up to (3/4)+(1/2) = (3/4)+(2/4) = 5/4 = 1&1/4
The whole part 1 is then added to the other whole parts 1 and 2 to get 1+2+1 = 4
Overall, the grand total is 4 & 1/4
An alternative way is to convert each mixed number to a decimal to get 1&1/2 = 1+1/2 = 1+0.5 = 1.5 and 2&3/4 = 2+3/4 = 2+0.75 = 2.75
Add up those decimals 1.5+2.75 = 4.25
then convert that result to a mixed number: 4.25 = 4+0.25 = 4+1/4 = 4&1/4
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Problem 38
<h3>Answer: C. Cubic feet</h3>
----------------
The units for volume follow the template "Cubic _____" where you'll write "feet", "inches", "centimeters" or whatever unit you are using in the blank.
Some other examples:
* cubic miles
* cubic meters
* cubic yards
Since you mentioned calculus, perhaps you're supposed to find the area by integration.
The square is circumscribed by a circle of radius 6, so its diagonal (equal to the diameter) has length 12. The lengths of a square's side and its diagonal occur in a ratio of 1 to sqrt(2), so the square has side length 6sqrt(2). This means its sides occur on the lines 
and 
.
Let 
be the region bounded by the line 
and the circle 
(the rightmost blue region). The right side of the circle can be expressed in terms of 
as a function of 
:
Then the area of this circular segment is
Substitute 
, so that 
Then the area of the entire blue region is 4 times this, a total of 
.
Alternatively, you can compute the area of in polar coordinates. The line becomes 
, while the circle is given by 
. The two curves intersect at 
, so that
so again the total area would be 
.
Or you can omit using calculus altogether and rely on some basic geometric facts. The region is a circular segment subtended by a central angle of 
radians. Then its area is
so the total area is, once again, .
An even simpler way is to subtract the area of the square from the area of the circle.
