Is the hundredth digit of decimal d greater than 5?

[Guest]

Source : Gmatprep 2

Is the hundredth digit of decimal d greater than 5?
1) The tenth digit of 10d is 7
2) The thousandth digit of d/10 is 7


Ans--D

I could not understand this problem. Can someone please help me understand this. Exam due on next week

[Saurav]

This problem requires understanding rules of Rounding off hte last digit. Usually .035 rounded to nearest 100th should be .04 and .034 rounded to the nearest 100th is .03

However, if remember from one of the similar questions GMAT rounds down 5 to zero. so .035 above becomes .03


Is the hundredth digit of decimal d greater than 5?

let us say the number is 0.ABCD (the decimal d)

1) The tenth digit of 10d is 7

d = 0.ABCD, hence 10d = A.BCD 10th digit of 10d = B = 7. which is 100th digit of d (=0.A7CD and thus bigger than 5) Sufficient

2) The thousandth digit of d/10 is 7

d = 0.ABCD, hence d/10 = 0.0ABCD 1000th digit of 10d = B = 7. which is 100th digit of d (=0.A7CD and thus bigger than 5) Sufficient

[Guest]

I don't understand the explanation- is there another way to explain?

[RonPurewal]

http://www.manhattangmat.com/forums/pos ... html#12967