$1601 \times 198 \div 49 - 1399 + 3878 = ?$

The sum of three numbers is $2$. The $1^{\text{st}}$ number is $\frac{1}{2}$ times the $2^{\text{nd}}$ number and the $3^{\text{rd}}$ number is $\frac{1}{4}$ times the $2^{\text{nd}}$ number. The $2^{\text{nd}}$ number is

$\frac{3}{7}$ of $\frac{49}{6}$ of $\frac{4}{7} = ?$

The largest natural number by which the product of three consecutive even natural numbers is always divisible,is

The difference between a two-digit number and the number obtained by interchanging the digits is $36$. What is the difference between the sum and the difference of the digits of the number if the ratio between the digits of the number is $1:2$?

$3149 \times 1?5 = 425115$