(i) By resolving 216 into prime factor, Show 216 = 2×2×2×3×3×3 By grouping the factors in triplets of equal factors, 216 = (2×2×2)×(3×3×3) Here, 216 can be grouped into triplets of equal factors, ∴ 216 = (2×3) = 6 Hence, 216 is cube of 6. (ii) By resolving 128 into prime factor, 128 = 2×2×2×2×2×2×2 By grouping the factors in triplets of equal factors, 128 = (2×2×2)×(2×2×2)×2 Here, 128 cannot be grouped into triplets of equal factors, we are left of with one factor 2 . ∴ 128 is not a perfect cube. (iii) By resolving 1000 into prime factor, 1000 = 2×2×2×5×5×5 By grouping the factors in triplets of equal factors, 1000 = (2×2×2)×(5×5×5) Here, 1000 can be grouped into triplets of equal factors, ∴ 1000 = (2×5) = 10 Hence, 1000 is cube of 10. (iv) By resolving 100 into prime factor, 100 = 2×2×5×5 Here, 100 cannot be grouped into triplets of equal factors. ∴ 100 is not a perfect cube. (v) By resolving 46656 into prime factor, 46656 = 2×2×2×2×2×2×3×3×3×3×3×3 By grouping the factors in triplets of equal factors, 46656 = (2×2×2)×(2×2×2)×(3×3×3)×(3×3×3) Here, 46656 can be grouped into triplets of equal factors, ∴ 46656 = (2×2×3×3) = 36 Hence, 46656 is cube of 36. What should be multiplied with 54000 to get a perfect cube?Hence the smallest number is 4.
Which number should be multiplied by 54 to get a perfect square?Answer: It should be multiplied by 6.
Is the smallest number by which 54 must be divided to obtain a perfect cube?Hence, 2 is the smallest number by which 54 should be divided so that the quotient is a perfect cube.
Which number when added to 54 gives the same result as when it is multiplied with 5 by 4?which number when added 5/4 gives the same result as when multiplied 5/4? x = 5.
|