One scientist kept 64 grams of a radioactive material in a container. after how many half lives will 1 gram of radioactive material be left in the container?

For this case we have an equation of the form:
 y = A * (b) ^ t
 Where,
 A: initial amount
 b: decrease rate
 t: periods of time
 Substituting values:
 y = 64 * (0.5) ^ t
 For y = 1 we have:
 1 = 64 * (0.5) ^ t
 Clearing t:
 (0.5) ^ t = 1/64
 log0.5 ((0.5) ^ t)) = log0.5 (1/64)
 t = log0.5 (1/64)
 t = 6
 
 it will be 1 gram of radioactive material left in the container after:
 6 half lives

True

Step-by-step explanation:

When she divides both numbers, she can find out how many stamps she bought. When you solve the equation, we can see that she bought 244 stamps. We can check this by doing inverse operations. 244 x 0.65 (the price for each stamp) = 158.60

i hope that this helps you :)