Question 4

What is cube root of 55555?

Given number is cube root of 55555 . By looking at the options we can infer that cube root of 55555 will be greater than 38 by a meagre amount of lets say 'x' :

55555 = $$(38+X)^3$$ 
55555 = 54872 +$$X^3$$ + 3(38)(X)(38+X)
683 = $$X^3$$ + 114(X)(38+X) 
      =  4332(X) +  114$$(X^2)$$ + $$X^3$$

"X" being a meagre value $$X^3$$ & 114$$(X^2)$$  doesn't contribute much to the 683 value . Hence X < $$\dfrac{\ 683}{4332}$$ .
Therefore X < 0.157.
Hence, the answer should be 38.15 .

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