$250 \%$ of $? \div 250 - 444 = 200$

$A$ fraction is greater than twice its reciprocal by $\frac{7}{15}$. What is the fraction?

$A$ fraction becomes $4$ when $1$ is added to both the numerator and denominator; and it becomes $7$ when $1$ is subtracted from both the numerator and denominator. The numerator of the given fraction is

The quotient arising from the division of $24446$ by a certain divisor is $79$ and the remainder is $35$. What is the divisor?

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

The greatest number among $3^{50}, 4^{40}, 5^{30}$ and $6^{20}$ is