Aptitude - Square Root and Cube Root - Discussion

The Easy method is (0.000216) means now you see in the cube numbers where the last digit 6 is coming.

6 is coming in 6 cubes the see after last 3 digits from the question that is zero, and finally, 0.06 is the answer.

By hypothesis cube root of .000216=(0.000216)^1/3.
=[(216)/10^6]^1/3.
we know that 6^3=216
So( 6^3)^1/3=6
and ll'y (10^6)^1/3=(10)^2
So (216/10^6)^1/3=[(6^3/10^6)]^1/3
=6/10^2
=6/100.
So The cube root of 0.000216 =0.06.

The Cube root of 10 is 1000.
Which means 6^3 /10^3.
i.e 6/10.

So, the correct answer should be 0.6 ( A).

Thank you all for the given explanation.

How here come 10^2? please explain.

I am not understanding it. Please, anyone explain it for me.

A simple method, just multiplies the options 3 times we will get the answer.

Which means, 0.06 * 0.06 * 0.06 = 0.000216, we know it is impossible to get an answer from option C and D.

@Reshma, the cube of 6 is 216. Not 196.

And, how is it 0.06? what should we do?
please, anyone, explain me.

Yes, it is 0.006.

I can't understand how come 6/10^2? please help me.