Answer:
Step-by-step explanation:
The exponential decrease formula that we must use is:
Where A is the amount of thorium as a function of time
is the initial amount and k is the decrease rate
We know that initially there are 50 gr and that you decay 50% every 1.9 years.
So
We solve the equation for k
After 22.8 years the amount of thorium that exists is:
Answer: 
Step-by-step explanation:
Given: The total number of ways of to choose 3 contestants out of 7 (including me and my friend)=35..................> Total outcomes.
Favorable outcomes = 2
Then the probability that me and my friend are both chosen =
Thus , the probability that me and my friend are both chosen =
Answer:
C≈157.08in
Step-by-step explanation:
C=2πr=2·π·25≈157.07963in
The population increases by a factor 1.0167 every year so the require figure is:
103 * 1 . 0167^5 = 112 million
Answer:
129
Step-by-step explanation:
180-51= 129
129 is corresponding with x
and corresponding angles are equal
so 129 is the answer
