Because you have more friends than oranges, you can assume that each person will only get part (or a fraction of) an orange. If you divide 5 oranges for 6 people, your equation looks like 5 / 6, so each person gets 5/6th of an orange, or about 0.833 oranges per person.
You are wrong because 0.167 into a fraction is 167/1000 and that isn't one of the options but when I did it 1 1/2=3/2=1.5 and 1/4=0.25 so I did 1.5 divide by 0.25 and it gave me 6 so that why I think that my answer is correct and yours is not.
