Question:
Which of the following numbers is not a perfect cube?
(a) 216
(b) 567
(c) 125
(d) 343
Solution:
(b) 216=6 x 6 x 6, 567 = 3 x 3 x 3 x 3 x 7
125 = 5 x 5 x 5, 343 = 7 x 7 x 7
Clearly, 567 is not a perfect cube, because in grouping, the factors in triplets of equal factors, we are left with two factors 3 x 7.
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.