Let x = number of students in each of the remaining rows
266 = (10 x 20) + (5 x 8) + 2x
266 - (10 x 20) - (5 x 8) = 2x
266 - 200 - 40 = 2x
26 = 2x
x = 26/2
x = 13
Answer: (total amount paid - $40) / 0.05
Step-by-step explanation:
Given the following :
Monthly fee = $40
Additional fee = $0.05 per minute on phone
Given the the amount paid for the month is available, number of minutes he was on phone can be determined thus :
Total amount to be paid = monthly fee + additional fee
Additional fee = $0.05 × n
Where n = number of minutes on phone
Hence,
Total amount paid = $40 + $0.05n
If the amount paid is known, the number of minutes on phone can be calculated thus;
(Total amount paid - monthly fee) = $0.05n
n = (Total amount paid - monthly fee) / fee per minute on phone
(total amount paid - $40) / 0.05
(12,756 kilometers) - (4,879 kilometers) = 7,877 kilometers
I assume 
has counterclockwise orientation when viewed from above.
By Stokes' theorem,
so we first compute the curl:
Then parameterize 
by
where the 
-component is obtained from
with 
and 
.
Take the normal vector to to be
Then the line integral is equal in value to the surface integral,
350 cm^2 (A for connections academy)
