A market maker has the following portfolio of options on the same underlying asset:

Type	Position	Delta of Option	Gamma of Option	Vega of Option
Call	-1,000	0.3	0.9	1.6
Call	600	0.2	0.5	1.0
Put	-2,000	-0.6	1.4	0.5

(a) Calculate the delta, gamma and vega of the portfolio. Provide an interpretation of the numbers (portfolio delta, portfolio gamma and portfolio vega) you calculated.

(b) One traded option is available. It has a delta of 0.8, a gamma of 4.0, and a vega of 2.0. How can the portfolio be made both delta and vega neutral?

(c) Two traded options are available: The first has a delta of 0.8, a gamma of 4.0, and a vega of 2.0. The second traded option has a delta of 0.5, a gamma of 2.0, and a vega of 6.0. How can the portfolio be made delta, gamma, and vega neutral?