$\left[(72)^{2} \div 36+(?)^{2}\right] \div 5=45$

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 $Y$?

$N$ is the largest two-digit number which,when divided by $3, 4,$ and $6,$ leaves the remainders $1, 2,$ and $4$ respectively. What is the remainder when $N$ is divided by $5$?

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

$\frac{(0.6^{3}-0.1^{3}-0.4^{3}-3 \times 0.6 \times 0.1 \times 0.4)}{(0.6^{2}+0.1^{2}+0.4^{2}+0.6 \times 0.1+0.6 \times 0.4-0.1 \times 0.4)}$

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