Problem $2$

A computer executes a benchmark which has $25{10}^6$ INT instructions, $55{10}^{6}FP$ instructions, $40{10}^6\frac{L}{S}$ instructions and $10{10}^6$ Branch instructions. The CPI for each type of instruction is $4,16,12,$ and $8,$ respectively. Assume that the processor has a $2GHz$ clock rate.

If the program has to run two times faster with the same clock rate, by how much must the CPI of FP instructions be improved?