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anemone
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X is a 4-digit perfect square all of whose decimal digits are less than seven. Increasing each digit by three we obtain a perfect square again. Find X.
anemone said:X is a 4-digit perfect square all of whose decimal digits are less than seven. Increasing each digit by three we obtain a perfect square again. Find X.
kaliprasad said:let the number be $x^2$ and adding 3333 we get $y^2$ and both x and y less than 100. so x + y less than 200
so $y^2-x^2= (y-x)(y+x) = 3333 = 33 * 101$
we need to find product of 2 numbers less than 200 and above is only combination
so y = 67 and x = 34
so $X = 34^2= 1156$
check:
now $y^2 = 67^2 = 4489 = 1156 + 3333$
which is tue
so ans is 1156
A perfect square is a number that is the result of multiplying a number by itself. For example, 4 is a perfect square because it is the result of multiplying 2 by itself (2 x 2 = 4).
To find a perfect square, you can take the square root of a number. For example, to find the perfect square of 25, you would take the square root of 25, which is 5. Then, you would multiply 5 by itself to get 25.
A 4-digit perfect square is a number that has 4 digits and is a perfect square. For example, the number 1681 is a 4-digit perfect square because it is the result of multiplying 41 by itself (41 x 41 = 1681).
There are 90 4-digit perfect squares. These numbers range from 1000 to 9801.
One way to quickly find a 4-digit perfect square is to use a calculator to take the square root of a number. Another way is to memorize a list of the most common perfect squares, such as 100, 144, 169, 196, 225, 256, 289, 324, 361, 400, 441, 484, 529, 576, 625, 676, 729, 784, 841, 900, 961, and 1024.