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Maths Puzzle
Numerical Ability
Age Problem
[x] denotes the greatest integer value just below x and {x} its fractional value. The sum of ( [x]cube) and ({x} square) is -7.19 . Find x
(A)-2.03
(B)-1.97
(C)-2.97
(D)-1.7
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- he following is what I think when I see this question:
The sum is -7.91. The negative sign makes me think that x is negative (and the options too).
[x]^3 has to an integer and negative. {x}^2 will be a small positive fractional value. The closest perfect cube integer to -7.91 is -8. [x]^3 must be -8 so [x] must be -2.
Then {x}^2 must be .09 giving {x} as .3 (Note here that {x} is always positive since [x] is less than or equal to x. So {x} is always the leftover positive fractional part)
Hence x = [x]+ {x} = -2 + .3 = -1.7 - 8 years agoHelpfull: Yes(1) No(0)
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