Which of following can never be ending of a perfect square?

How many pairs of natural numbers is there the difference of whose squares are 45.

397 × 397 + 104 × 104 + 2 × 397 × 104 = ?

Each member of a picnic party contributed twice as many rupees as the total number of members as the the total collectio…

Find the remainder when 54<sup>124</sup> is divided by 17.

If the product of two positive numbers be 1575 and their ration is 7 : 9, then the greatest number is :

By how much does $$\frac{6}{{\frac{7}{8}}}$$ exceed $$\frac{{\frac{6}{7}}}{8}$$ ?

A number consists of two digits such that the digit in the ten's place is less by 2 than the digit in the unit place. Th…