Home › CBSE Class 8 › Mathematics › Squares and Square Roots › Using prime factorisation, √324 equals:
Using prime factorisation, √324 equals:
A12
B18
C21
D24
Answer & Solution
Correct answer: B. 18
324 = 2² × 3⁴ = (2 × 3²)² = (2 × 9)² = 18². So √324 = 18. (Pairs of primes give the square root: take one factor from each pair.)
Related questions
A right triangle has hypotenuse 5 cm and one side 3 cm. The third side squared is:90 = 2 x 3 x 3 x 5. Since 2 and 5 are unpaired, 90 is:The square root of 6400 is:48 = 2x2x2x2x3 has one unpaired 3. The smallest number to multiply 48 by to get a perfect 256 = 2x2x2x2x2x2x2x2. Pairing the factors, its square root is:Subtracting 1, 3, 5, ... from 81 reaches 0 at the 9th step. So the square root of 81 is:A perfect square has two integral square roots; the root symbol denotes only the:Finding a number whose square is known is called finding the: