A machine has only one single-core CPU. There are two processes, P₁ and P₂, in the memory. P₁ needs 8 second to complete on its own; P₂ needs 4 second to complete on its own. The scheduler requires 0.25 second to switch process. Process termination does not need any extra time.

1)If the two process are running sequentially (run P₁ first, then P₂), how long does it take to complete both processes?

2)If the two process are running in multiprogramming (pseudo parallel), in which the scheduler switches process once per second (if there are more than one process available), how long does it take to complete both processes (start with process P₁)?