Answer:
Every week, the radioactivity decreases by a factor of 5
After 1 week, it goes from 5,000 to 1,000
2 weeks 1,000 / 5 =200
3 weeks 200 / 5 = 40
4 weeks 40 / 5 = 8
5 weeks 8 / 5 = 1.6
6 weeks 1.6 / 5 = 0.064
7 weeks 0.064 / 5 = 0.0128
8 weeks .0128 / 5 = 0.00256
9 weeks 0.00256 / 5 = 0.000512
10 weeks 0.000512 / 5 = 0.0001024
Step-by-step explanation:
They are equivalent. combine like terms on the first one and 9x-4x+25 can be simplified to 5x+25.
Answer:
P(A) = 44.44%
P(B) = 50%
P(B|A) = 37.5%
P(B|A) different from P(B).
A and B are independent.
Step-by-step explanation:
If we have a total of 180 students, and 80 of them have a Playstation, we have that P(A) = 80/180 = 0.4444 = 44.44%
If we have 90 students that have a Xbox, we have that P(B) = 90/180 = 0.5 = 50%
If we have 30 students that have both consoles, we have that P(A and B) = 30/180 = 0.1667 = 16.67%
To find P(B|A), we will find for a student that has an Xbox inside the group of students that has a Playstation, that is, we have 30 students in a total of 80 students, so P(B|A) = 30/80 = 0.375 = 37.5%
P(B|A) is different from P(B), the first is 37.5% and the second is 50%, so events A and B are independent events.
