0.7683 + 0.369 + 0.05 + 0.8 = ?

Answer: Option C

Explanation:

9/11 = .818 , 8/9 = .88 , 3/5 = .6, 4/7 = .571

So order is 8/9 > 9/11 > 3/5 > 4/7

Answer: Option C

Explanation:

\begin{aligned}
a^3 + b^3 = (a+b)(a^2 + b^2 - ab)
\end{aligned}

\begin{aligned}
= \frac{10.3^3 + 1^3}
{10.3^2 + 1^2 - 10.3 \times 1}
\end{aligned}

\begin{aligned}
= (a+b) = (10.3+1) = 11.3
\end{aligned}

Answer: Option A

Explanation:

when there is bar above a number, we can simplify it by dividing with 9's (equal to the number below bar, in this question 2 digits are below bar)

Answer: Option C

Explanation:

Can be easily solved with following formula
\begin{aligned}
a^2 - b^2 = (a - b)(a + b)
\end{aligned}

Answer: Option C

Explanation:

1/0.04 = (1 * 100)/4 = 100/4 = 25