b. (896) An algorithm takes 15 seconds to solve a problem of size 1000. If the algorithm is quadratic-i.e., runs as O(N2), how large a problem can be solved in 60 seconds? (a) 2000 (b) 4000 (c) 6000 (d) none of the above b. (896) An algorithm takes 15 seconds to solve a problem of size 1000. If the algorithm is quadratic-i.e., runs as O(N2), how large a problem can be solved in 60 seconds? (a) 2000 (b) 4000 (c) 6000 (d) none of the above