Please help me #e484847572
2 answers:
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Answer:
w-5
Step-by-step explanation:
-4w20
4w-20
w-5
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:
<em>(A) 560 students</em>
<em>(B) P = 0.41</em>
Step-by-step explanation:
<em>(Please check the attached picture for more details)</em>
As given, a survey of 1000 students found that:
41% of the surveyed students were freshmen
=> 1000 x 41/100 = 410 surveyed students were freshmen
31% were juniors
=> 1000 x 31/100 = 310 surveyed students were junior
67% of surveyed students lived on the college campus
=> 1000 x 67/100 = 670 surveyed students lived on the campus
<em>(A) 260 of the surveyed students were freshmen living on the campus</em>
=> A = 410 - 260 = 150 surveyed students were freshmen NOT living on the campus
=> B = 670 - 260 = 410 surveyed students were not freshmen living on the campus
=> The number of surveyed students who were either freshmen or living on the campus:
N = A + B = 150 + 410 = 560
<em>(B) From a previous survey you know that of interviewed juniors, only 23% live on campus (we don't really need this)</em>
=>The probability a surveyed student is a junior or someone that lives on campus: P = (670 - 260)/1000 = 0.41
I hope this helps!
