Question

which of the following numbers are not in standard form (a)21.56×10 (b)215.6×10^4 (c) 2.156×10^6​

Answer 1

Answer:

Prime factorizing 243, we get,

243=3×3×3×3×3=3

5

.

We know, a perfect cube has multiples of 3 as powers of prime factors.

Here, number of 3's is 5.

So we need to multiply another 3 in the factorization to make 243 a perfect cube.

Hence, the smallest number by which 243 must be multiplied to obtain a perfect cube is 3.