$A$ number when divided by the sum of $555$ and $445$ gives two times their difference as quotient and $30$ as the remainder. The number is

What is the arithmetic mean of first $20$ odd natural numbers?

The price of commodity $X$ increases by $40 \text{ paise}$ every year,while the price of commodity $Y$ increases by $15 \text{ paise}$ every year. If in $2001$,the price of commodity $X$ was $Rs. 4.20$ and that of $Y$ was $Rs. 6.30$,in which year will commodity $X$ cost $40 \text{ paise}$ more than commodity $Y$?

The sum of squares of two numbers is $68$ and the square of their difference is $36$. The product of the two numbers is

What is the unit digit in $\{(6374)^{1793} \times (625)^{317} \times (341)^{491}\}?$

How many $3$-digit numbers are completely divisible by $6$?