Answer:
probability that you and your 3 friends will be selected.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
In this question, the order in which the volunteers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

Desired outcomes:
You and the 3 friends(4 people), from a set of 4. So

Total outcomes:
20 people from a set of 20. So

Probability:

probability that you and your 3 friends will be selected.
Answer:
1 tree every 45 mins
Step-by-step explanation:
Answer:
0.054
Step-by-step explanation:
Using the compound formula A=P(1+r/n)^nt we can plug in the numbers we know. A being the total, P the initial amount, n is the number of compounds in a year, and t is the number of years passing. So 10300= 4900(1+ r/2)^2(14). We have to isolate r in order to find the rate. We can divide both sides by 4900, giving us 103/49= (1+ r/2)^28. Then we take the 28 square root from both sides. 1.02689= 1 + r/2. Subtract 1 from both sides. 0.02689= r/2. Then multiply both sides by two. r= 0.054.
From V= 4/3*pi*r^3
<span>dV/dt = 4pi(r^2)dr/dt </span>
<span>so when dV/dt=30 and r = 19 </span>
<span>30 = 4pi(361)dr/dt </span>
<span>dr/dt = 30/[4pi(361)] </span>
<span>now in </span>
<span>A = 4pir^2 </span>
<span>dA/dt = 8pi(r)dr/dt </span>
<span>= 8pi(19)*30/[4pi(361)] </span>
<span>= you finish it.</span>
<span>HOPE THIS HELPS.
</span>
This is an obtuse triangle because one angle of it is greater than 90 degrees :)