$7 \%$ of $4000 - 12 \%$ of $550$

The sum of a non-$zero$ number and twice its reciprocal is $\frac{33}{4}$. Find the number.

$A$ boy added all natural numbers from $1$ to $12,$ however he added one number twice due to which the sum became $80.$ What is the number which he added twice?

One-fifth of a number is equal to $\frac{5}{8}$ of another number. If $35$ is added to the first number,it becomes four times the second number. The second number is

$36 + 451 \div 11$

What least number must be subtracted from $1294$ so that the remainder when divided by $9, 11, 13$ will leave in each case the same remainder $6$?