What is the difference between the biggest and the smallest fraction among 2/3 , 3/4 , 4/5 and 5/6 ?

Answer: Option A

Converting each of the given fractions into decimal form, we get :
$$\frac{2}{3}$$ = 0.66
$$\frac{3}{4}$$ = 0.75
$$\frac{4}{5}$$ = 0.8
$$\frac{5}{6}$$ = 0.833
Since 0.833 > 0.8 > 0.75 > 0.66
So, $$\frac{5}{6}$$ > $$\frac{4}{5}$$ > $$\frac{3}{4}$$ > $$\frac{2}{3}$$
∴ Required difference = $$\left(\frac{5}{6}-\frac{2}{3}\right)=\frac{1}{6}$$