The average of four consecutive odd numbers is $40$. What is the largest number?

What least number should be added to $3529$ so that it becomes a perfect square?

If the product of three consecutive numbers is $210$ then sum of the two smaller number is:

If ${\left(\frac{1}{5}\right)}^{3y}=0.008$, then the value of ${\left(0.25\right)}^y$ is:

Three numbers are such that their sum is $50$. Product is $3750$ and the sum of their reciprocals is $\frac{31}{150}$. Find the sum of the squares of the three numbers.