幾條數學題

The figure shows a prism whose base is a parallelogram(base:16cm,height:12cm,斜邊:13cm).If the tital area is 3284cm2,find its volume.
let parallelogram's height = m
total area = 2*(16*12) + 2*(13*12) + 2*(16*m)
3284 = 2*(16*12) + 2*(13*12) + 2*(16*m)
m=80.875
its volume=16*80.875*12=15528cm^2

Consider the sequence -3,9,-27
the general term,hence the 100th term
if -3 is the first term, and 9 is the second term....
2nd/1st=9/(-3)=-3, also 3rd/2nd=-27/9=-3
so the term equation is f(x) = (-3)^x
hence the 100th term is f(100) = (-3)^100 or 3^100

Find the R.F. of a map if the scale of the map is
a)3cm:24m
=3cm:24*100cm
=3cm:2400cm
=1:800
b)1.5cm:4.5km
=1.5cm:4.5*1000*100cm
=1.5cm:450,000cm
=1:300,000

Which is the lower rate:630l/h or150c.c./s
sorry that i don't know what is c.c.