Let me help you visualize this one.
Let's say we have 12 chickens.
OOOOOOOOOOOO
We divide this group in half (1/2 who tried to cross the road.)
OOOOOO
And here, we need to get 3/4 of the 6 left.
3/4 can be represented as 0.75 of 1.
6 times 0.75 equals to 4.5.
OOOOC (Woah, that chicken is split in half!)
What fraction is 4.5 of the original amount?
Well, that's for you to find out! Good luck in solving this question.
