Question

What is the least no which must be added to 115580 to make perfect square

Answer 1

20 should be added to make a perfect square. take a look at pictures.
here 339 come and there are also some rest so we need square of 340 to calculate what should be added.

Answer 2

Answer:

The number, 80, is divisible by 4, so the entire number 115,580 is also divisible by 4. The number 115,580 ends in 0 so it may be a divisible by 25, a perfect square because all multiples of 5 end in 0 or 5.

Divide 4, a perfect square, into 115580 and you get 28895. This not divisible by a multiple of 5 but could possibly be if one adds 5 to 28895 to make 28900. Take the square root of 28900 and you get 170.

Thus 2^2 times 170^2 = 115600, so it looks like one must ADD 20 to 115580 to get a perfect square. 2* 170 = 340 and 340 squared = 115600.