Question 1110062
Look at all of the possibilities there are 8 {{{(2^3)}}} of them.
BBB
BBG
BGB
BGG
GBB
GBG
GGB
GGG
So then,
a) 2B and 1G: BBG, BGB, GBB - 3 outcomes.
{{{P=3/8}}}
b) Let's do it backwards. No boys - GGG - 1 outcome.
The complement is 7. 
{{{P=7/8}}}
c) Again, use the complement, BBB and GGG - 2 outcomes so,
{{{P=6/8=3/4}}}
d) So no girls or 1 girl, BBB, BBG, BGB, GBB, 4 outcomes,
{{{P=4/8=1/2}}}