$1523.89 \div 19.95 + 496.28 + 249.927 = ?$

The numerator and denominator of a fraction are in the ratio of $2:3$. If $6$ is subtracted from the numerator,the result is a fraction that has a value $\frac{2}{3}$ of the original fraction. The numerator of the original fraction is

$A$ fraction is greater than its reciprocal by $\frac{9}{20}$. What is the fraction?

The least positive integer that should be subtracted from $3011 \times 3012$ so that the difference is a perfect square,is

Two baskets together have $640$ oranges. If $\frac{1}{5}$ of the oranges in the first basket are taken to the second basket,the number of oranges in both baskets becomes equal. The number of oranges in the first basket is:

$9229.789 - 5021.832 + 1496.989 = ?$