Question

what least no must be added from 6249 to get a perfect square no? what is this perfect square number? also,find its square root.

Answer 1

If we 
√6429 = 79.05061

but if we
81² = 6561
                               (80² = 6400, which is less than 6429)
∴  6561 - 6429 = 132

∵ 132 must be added to 6429 to make it a perfect square.
And if we √6561 then we get 81.