Squares and Square Roots

The least square number which is exactly divisible by 10, 12, 15 and 18, is

A general wishes to arrange his 36581 soldiers in the form of a square. After arranging them he found that some of them are left over. The number of soldiers left over is

A man plants 15129 apple trees in his garden and arrange them so that there are as many rows as there are apple trees in each row, then the number of rows is

The greatest perfect square of a natural number smaller than (51)2 is

The least four digit number which is a perfect square, is

Which of the following is a perfect square of an even number ?