Question 3. Given the following MIPS sequence executed in a 5-stage pipeline MIPS processors (IF, ID, EXE, MEM, WB): sub $2, $1, $3 and $12, $2, $5 or $13, $6, $2 add $14, $2, $2 SW $15,100 ($2) a. If only the stall insertion method is used for data hazards, what is execution time of the sequence of instructions in term of cycles? b. What is the average CPI of the above sequence when only the stall insertion method is used for data hazard? c. When both the forwarding method and the stall insertion method are used, what is the speed-up compared to stall insertion