The half-life is 29 years. 116 : 29 = 4 So we will have 4 periods of half-life: ( 1/2 )^4 = 1/16 150 g * 1/16 = 9.375 g Answer: 9.375 g of strontium -90 will remain after 116 years.
Let be a random variable denoting the amount of winnings in any given round of the game. There is some probability of winning where , while , assuming these are the only two possible outcomes. So we have