Arithmetic : Rounding

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Arithmetic : Rounding

by anirudhbhalotia » Thu Jan 13, 2011 10:25 pm
d=0.43t7

If t denotes the thousandths digit in the decimal representation of d above, what digit is t ?

1. If d were rounded to the nearest hundredth, the result would be 0.44.

2.If d were rounded to the nearest thousandth, the result would be 0.436.


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by Anurag@Gurome » Thu Jan 13, 2011 11:10 pm
anirudhbhalotia wrote: d=0.43t7

If t denotes the thousandths digit in the decimal representation of d above, what digit is t ?

1. If d were rounded to the nearest hundredth, the result would be 0.44.
2.If d were rounded to the nearest thousandth, the result would be 0.436.
d = 0.43t7

Statement 1: d rounded to the nearest hundredth = 0.44
The hundredths digit of d is 3.
But rounding to nearest hundredth makes it 4.
Hence, the thousandth digit of d, i.e. ≥ 5.

Not sufficient

Statement 2: d rounded to the nearest thousandth = 0.436
The thousandths digit of d is t and the ten-thousandth digit of d is 7.
Thus, rounding to the nearest thousandth will increase the thousandth digit by 1.
Hence, the thousandth digit of d, i.e. t = (6 - 1) = 5

Sufficient

The correct answer is B.
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