If the height of the cylinder in the example were 12 centimeters, how would the volume compare

What is the 12th term of b(n)=-4-2(n-1)

Can some one me with these questions

Raymond just got done jumping at super bounce trampoline center. the total cost of his session was $43.25 . he had to pay a $7 entrance fee and $1.25 for every minute he was on the trampoline. write an equation to determine the number of minutes (t) that raymond was on the trampoline.