By Stokes' theorem,

where

is the circular boundary of the hemisphere

in the

-

plane. We can parameterize the boundary via the "standard" choice of polar coordinates, setting

where

. Then the line integral is


We can check this result by evaluating the equivalent surface integral. We have

and we can parameterize

by

so that

where

and

. Then,

as expected.
Take off 3 of the pennies and the 5 that remain would be 3 nickels and 2 dimes
2 dimes=20 cents
3 nickels = 15 cents
3 pennies=3 cents
Or these 8 coins = 38 cents
i would say D) 12 is your answer