Question

I am a decimal

Answer 1

0.6<2x<0.65 (because it's closer to 6)
0.3<x<0.325

Since the thousandths digit of 2x is 2, then the thousandths digit of x is 1 or 6, so the decimal could be 0.301, 0.302, 0.311, 0.312, 0.321

Hope this helps :)

Answer 2

Numbers greater than 0.3 and less then 0.35 are between .6 and .7 when doubled.

Lets assume it is a decimal that goes up to the thousandths. 
0.310 to 0.324 Would be closer to .6 than .7. We know the thousands digit has to be a 1 or a 6 because its double ends in a two. So it looks like our options are .311, .316 and .321.