a. There are 11 people, so the chance of picking a man first is 6/11, leaving 5 men and 5 women. If the second is also a man, the chances of picking one are 1/2; for the third man it's 4/9, then 3/8 and 2/7. The combined probability is 6/11*1/2*4/9*3/8*2/7=1.3% approx.
b. Let's assume that the order is 2 men then 3 women (we address the problem of other orders later). For the two men the combined probability is 6/11*1/2=3/11. There are 4 men and 5 women left, so the combined probabilities for the women are 5/9*1/2*3/7=15/126=5/42=11.9% approx. But we have to consider how many ways 2 men and 3 women can be selected:
MMWWW, MWMWW, MWWMW, MWWWM, WMMWW, WMWMW, WMWWM, WWMMW, WWMWM, WWWMM.
Therefore we need to multiply the combined probabilities by 10: 3/11*5/42*10=32.47% approx.