For this case we have the following exponential equation:
 y = A (b) ^ t
 Where,
 A: initial amount
 b: decrease rate
 t: time in hours
 We then have to rewrite the equation for this problem:
 y = 200 * (0.5) ^ ((1/16) * t)
 For t = 29 hours we have:
 y = 200 * (0.5) ^ ((1/16) * 29)
 y = 56.93943174 mg
 Answer:
 It will remain 56.94 mg after 29 hours
