Tuesday, November 18, 2008

Problem Solving - 55

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

Answer: E

RULE: If denominator of a fraction has just the prime factors of 2 or 5 or both it is terminating otherwise not

128 = 2*2*2*2*2*2*2 => has only factors of 2..hence the ans