A Quad-core server has a total computing capacity of 8 GHz (4 x 2 GHz). Virtual machines of various sizes running multiples tasks can be placed on each core of the server, provided there is sufficient computing capacity available on the sever core. Given below are the virtual machine requests (in GHz) that need to be placed on the server for execution.

1.6, 0.7, 0.5, 1.2, 0.8, 0.6, 1.3, 1.0, 0.3

What is the optimal placement of the virtual machines on the server if:

(a) the virtual machine requests arrive in the given order

(b) all virtual machine requests are available in advance.

Note: It is not necessary that all virtual machine request would be satisfied.