A popular database program is taking about 15 seconds to do a benchmark database computation. This must be reduced to 5 seconds. The CPU is currently running at a cycle rate of 250MHz. The semiconductor researchers, meanwhile, have discovered a new kind of technology that allows clock rates to be increased substantially, but this increase will affect the rest of the CPU design, causing the new machine to require 25% more clock cycles as the current machine to do the same job. Calculate the minimum clock rate that must be achieved, assuming that the time spent on I/O is negligible.