Can someone please help me answer these two problems? Thank you!!!

Find the sum to the equation 3+6+9+

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

The tuition costs, c, for a local community college are modeled by c(h) = 250 + 200h, where h represents the number of credit hours taken. the local state university has tuition costs, s, modeled by the function s(h) = 300 + 180h. how many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.