3640 ÷ 14*16 + 340 = ?

Answer: Option D

Explanation:

\begin{aligned}
= 3034 -( \frac{1002}{2004} \times 100)
\end{aligned}
\begin{aligned}
= 3034 - 50 = 2984
\end{aligned}

Answer: Option A

Answer: Option D

Explanation:

Let the boys are X, then girls are 7X, total = X+7X = 8X

So it should be multiple of 8, 30 is not a multiple of 8.

Answer: Option C

Explanation:

Remember the formula, if not then cram it :)
\begin{aligned} 2ab = (a^2 + b^2)- (a-b)^2 \end{aligned}
=> 2ab = 29 - 9 = 20
=> ab = 10

Answer: Option C

Explanation:

We need so simple divide 42.5/0.85,
=(4250/85) = 50