Question

Without actual division find which are terminating decimals a)5/12 b)16/125

Answer 1

b) 16/125 is a terminating decimal..........

Answer 2

For terminating decimal the prime factorisation of denominator should only contain the factor 2 or factor 5 or both factors 2 and 5. 
prime factorisation of denominator containing factors 2 & any other number or factors 5 & any other number or faciors 2,5 & any other  number are non terminating decimals.
a)5/12 is not a terminating decimal since the prime factorisation of 12 contains the factors  2 & 3 i.e., 12=2X2X3
b)16/125 is a terminating decimal since the prime factorisation of 125 contains the factors only 5 i.e.,125=5X5X5