No of branch instruction taken = 2/3 * 4500 = 3000
since these 3000 instructions skip the next 5 instruction, total no of instruction = 25000 – 3000*5 = 10000
Time in non-pipeline = 10000*5 = 50000 cycle
Time in pipeline = (10000 + 5-1) + 3000*2 = 16004
Speed-up = 50000/16004 = 3.124