Answer:
120 grams will be left after 180 years.
Step-by-step explanation:
A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay and its given by

where,
= quantity of the substance remaining
= initial quantity of the substance
= time elapsed
= half life of the substance
From the information given we know that:
- The initial quantity is 480 g,
- The half-life is 90 years,
- 180 years is the time elapsed.
And we want to find how much will be left. For this we use the above formula.

120 grams will be left after 180 years.
Answer:
240
Step-by-step explanation:
20 times 24 is 240
20 x 24 = 240
The question is incomplete. Below you will find the missing contents.
The correct match of events with order are,
- P(A)P(B|A) - Dependent event
- P(A)+P(B) - Mutually exclusive events
- P(A and B)/P(A) - Conditional events
- P(A) . P(B) - Independent Events
- P(A)+P(B) -P(A and B) - not Mutually exclusive events.
When two events A and B are independent then,
P(A and B)=P(A).P(B)
when A and B are dependent events then,
P(A and B) = P(A) . P(B|A)
When two events A and B are mutually exclusive events then,
P(A and B)=0
So, P(A or B) = P(A) + P(B) - P(A and B) = P(A) + P(B)
P(A) + P(B) = P(A or B)
When events are not mutually exclusive then the general relation is,
P(A or B) = P(A) + P(B) - P(A and B)
If the probability of the event B conditioned by A is given by,

Hence the correct match are -
Dependent event
Mutually exclusive events
Conditional events
Independent Events
not Mutually exclusive events.
Learn more about Probability of Events here -
brainly.com/question/79654680
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Just draw one empty circle for 1 and then a filled circle for -1 so then it's 1-1 which equals 0