The distance from the sun to mars is an average of 2.1¯ times the distance from the sun to venus.how can this repeating decimal
1 answer:
We are given repeating decimal number 2.1¯.
We know 2.1¯ = 2.1111..... repeating 1's.
Let us assume x is a fraction equals given repating decimal number.
And set it as a first eqaution.
x = 2.1111..... ------------- (equation 1).
Multiplying equation both side by 10 ( because only one digit is repeating after decimal, we multiply by 10).
On multiplying by 10 we get
10*x = 10*2.1111.....
10x = 21.1111...... ----------------- (equation 2)
Subtracting equation 1 from equation 2, we get
10x = 21.1111......
-x = -2.1111.....
_____________
9x = 19.
Now, dividing both sides by 9. we get
Therefore, 2.1¯ repeating decimal be expressed as a fraction .
So, the correct option is option c. 19/9.
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Answer:
46.67% probability that they flew with airline B.
Step-by-step explanation:
We have these following probabilities:
A 40% probability that a traveler chooses airline A.
A 35% probability that a traveled chooses airline B.
A 25% probability that a traveler chooses airline C.
If a passenger chooses airline A, a 10% probability that he arrives late.
If a passenger chooses airline B, a 15% probability that he arrives late.
If a passenger chooses airline C, a 8% probability that he arrives late.
If a randomly selected traveler is on a flight from Seattle which arrives late to Sydney, what is the probability that they flew with airline B?
This can be formulated as the following problem:
What is the probability of B happening, knowing that A has happened.
It can be calculated by the following formula
Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.
So
What is the probability that the traveler flew with airline B, given that he was late?
P(B) is the probability that he flew with airline B.
So
P(A/B) is the probability of being late when traveling with airline B. So P(A/B) = 0.15.
P(A) is the probability of being late. This is the sum of 10% of 40%(airline A), 15% of 35%(airline B) and 8% of 25%(airline C).
So
Probability
46.67% probability that they flew with airline B.