Respuesta :

tramserran

Answer: 71.2 mg

Step-by-step explanation:

A = P(1 - r)ⁿ       where:

  • P is the initial amount
  • r is the rate of decrease
  • n is the time  

A = 400(1 - 0.25)⁶

   = 400(0.75)⁶

   = 400(0.178)

   = 71.2