Answer: 
Step-by-step explanation:
Given
Population of dust particle doubles every 30 minutes
If the initial sample is 21 grams
The model to predict the population will be

Where t=time in hours
A day has 24 hours . So, for 2 days time is 48 hours
Population is given by
6a+15+5a-10
11a+5 is the answer :D
mutiply 3 to 2a and 5 / 5 to a and -2 you will get 6a+15+5a-10 then 6a+5a and 15-10 would be 11a+5
sorry I'm not good at explaining, ask me if you got a question. :D
The probability that two of the coins will be tails is 1/2
It is 1/2 because "at least two tails" means that two tails and the rest of the number of tails, which is 3. In total the three coins have 6 sides. The chance of having two tails and one is three out of 6, simplified is 1/2 ;)
Answer:
-5
Step-by-step explanation:
-5 shows up most frequently in this set of numbers.
18 / 25 = 0.72 per marker