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

Answer: Option C

Explanation:

Use following formula to solve it quickly
\begin{aligned}
\frac{a^2-b^2}{a-b}=\frac{(a+b)(a-b)}{(a-b)} = (a+b)
\end{aligned}
= (2.39+1.61) = 4

Answer: Option D

Answer: Option B

Answer: Option A

Explanation:

\begin{aligned}
6.\overline{46} = 6 + 0.\overline{46}
= 6 + \frac{46}{99}
= 6\frac{46}{99} = \frac{640}{99}
\end{aligned}

Answer: Option D

Explanation:

5/8 = .625, 7/12 = .5833, 3/4 = .75, 13/16 = .8125

So order will be
7/12 < 5/8 < 3/4< 13/16