***Timed Test Please Help*** If f(x) = 3x and g(x)-1/x, what is the domain of (g0f)(x)? x>0 all real numbers except x = 0 x<0 all real numbers

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?