Aman has 729 coins. He gives only a part of these coins to his cousin as his birthday gift. This part is the square root of 729. How many coins did his cousin get?
27
The square root of 729 should have 3 or 7 in its unit place. Because square of 3 and 7 has 9 in it's units place. Only 27 satisfies this.
Thus, Aman's cousin gets 27 coins as a birthday gift.
Also, we can find the square root using prime factorization as
729=3×3×3×3×3×3
729=36
Square root of 729 is equal to
√729=√36=33=27