How do you use a congruence statement to find missing measures

Can someone me i’m confused. will give brainliest and a whole bunch of points

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

1. how do you convert the repeating, nonterminating decimal 0. to a fraction? explain the process as you solve the problem.