V.2 Find the smallest number by which 1100 must be multiplied so that the product becomes a perfect square.

V.2 Find the smallest number by which 1100 must be multiplied so that the product becomes a perfect square. Also, find the square root of the perfect square so obtained.

The Correct Answer and Explanation is:

To solve the problem:

V.2 Find the smallest number by which 1100 must be multiplied so that the product becomes a perfect square. Also, find the square root of the perfect square so obtained.


Correct Answer:

Smallest number = 11
Perfect square = 1100 × 11 = 12100
Square root = √12100 = 110


📘 Explanation (Approx. 300 words):

To make a number into a perfect square, we need to ensure that all the prime factors of the number appear in even powers. Let us begin by performing the prime factorization of 1100.

Step 1: Prime factorization of 11001100=11×100=11×(10×10)=11×(2×5)×(2×5)=11×22×521100 = 11 × 100 = 11 × (10 × 10) = 11 × (2 × 5) × (2 × 5) = 11 × 2^2 × 5^21100=11×100=11×(10×10)=11×(2×5)×(2×5)=11×22×52

So,1100=22×52×1111100 = 2^2 × 5^2 × 11^11100=22×52×111

Now, we observe the powers of the prime factors:

  • 222^222: Even power – this is fine.
  • 525^252: Even power – this is fine.
  • 11111^1111: Odd power – this needs to be made even.

To make the power of 11 even, we must multiply the number by another 11. This will give:1100×11=(22×52×111)×11=22×52×1121100 × 11 = (2^2 × 5^2 × 11^1) × 11 = 2^2 × 5^2 × 11^21100×11=(22×52×111)×11=22×52×112

Now, all prime factors have even powers, so the product is a perfect square.


Step 2: Find the square root of the resulting perfect square

We now compute:1100×11=121001100 × 11 = 121001100×11=12100

Take the square root of 12100:12100=22×52×112=2×5×11=110\sqrt{12100} = \sqrt{2^2 × 5^2 × 11^2} = 2 × 5 × 11 = 11012100​=22×52×112​=2×5×11=110


🟩 Final Answer:

  • Smallest number to multiply by = 11
  • Perfect square = 12100
  • Square root = 110
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