Answer:
D.
Step-by-step explanation:
In order to eliminate, the numbers must eliminate. If the second equation is multiplied by 3, then the 3 and the -3 can be eliminated. Since it is multiple choice, we can plug in x = 12 and y = 10 to see if they are correct. 12 + 30 = 42 and 24 - 10 = 14, so D is correct.
3*6.022*10^23 no of molecules in 3.0 moles of sucrose
A) the probability it is brown would be 50%; the probability it is yellow or blue would be 35%; the probability it is not green is 95%; the probability it is striped is 0%.
B) the probability of all brown would be 12.5%; the probability that the third one is the first red one drawn is 8.1%; the probability that none are yellow is 61.4%; the probability that at least one is green is 14.3%.
Explanation:
A) The probability that it is brown is the percentage of brown we have. Brown is not listed, so we subtract what we are given from 100%:
100-(15+10+20+5) = 100-(50) = 50%. The probability that one drawn is yellow or blue would be the two percentages added together: 15+20 = 35%. The probability that it is not green would be the percentage of green subtracted from 100: 100-5=95%. Since there are no striped candies listed, the probability is 0%.
B) Since we have an infinite supply of candy, we will treat these as independent events. All 3 being brown is found by taking the probability that one is brown and multiplying it 3 times:
0.5*0.5*0.5 = 0.125 = 12.5%.
To find the probability that the first one that is red is the third one drawn, we take the probability that it is NOT red, 100-10 = 90% = 0.9, for the first two, and the probability that it IS red, 10% = 0.1, for the last:
0.9*0.9*0.1 = 0.081 = 8.1%.
The probability that none are yellow is found by raising the probability that the first one is not yellow, 100-15=85%=0.85, to the third power:
0.85^3 = 0.614 = 61.4%.
The probability that at least one is green is computed by subtracting 1-(probability of no green). We first find the probability that all three are NOT green:
0.95^3 = 0.857375
1-0.857375 = 0.143 = 14.3%.
One way to do this is to notice
Then
We have
and since 
has a period of 
,
and so
It is a trick question 13+13 DOES equal 26
