Recurring decimal---lengthy problem

prachich1987 wrote:I found below problem in one of the book.
Will such type of problems appear in actual GMAT.
If yes, is there any short method of solving the same?Plz guide

Which of the following fractions has a decimal equivalent that is a terminating decimal?
A] 10/189
B] 15/196
C] 16/225
D]25/144
E) 39/128

I have not seen till date that GMAT play a Trick on Recurring Decimal... But this problem is not that tough.

If it appears then you cannot blame GMAC

Terminating Decimal

A decimal representation written with a repeating final 0 is said to terminate before these zeros.
13/4 = 3.2500000...
Instead of 3.2500000... we write 3.25

The general formula of a Terminating Decimal is represented as K/[(2)^m * (5)^n]

Non-Terminating Decimal

This can be repeating or non repeating but Never stops. Means we will never get consecutive 0's at any certain point of time in the decimal part (Unlike Terminating One)

As Rahul has shown above only 128 is contains 2 (as 128 = 2^7) it will present a Terminating Decimal.

Thus E is the answer.

PS: https://en.wikipedia.org/wiki/Repeating_decimal