A group of 8 friends (5 girls and 3 boys) plans to watch a movie, but they have only 5 tickets. If they randomly decide who will
2 answers:
Answer:
D. 0.821
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
The combinations formula is important to solve this question:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
Desired outcomes
The order is not important. For example, Elisa, Laura and Roze is the same outcome as Roze, Elisa and Laura. This is why we use the combinations formula.
At least 3 girls.
3 girls
3 girls from a set of 5 and 2 boys from a set of 3. So
4 girls
4 girls from a set of 5 and 1 boy from a set of 3. So
5 girls
5 girls from a set of 5
Total outcomes
5 from a set of 8. So
Probability
So the correct answer is:
D. 0.821
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Answer: Choice D
b greater-than 3 and StartFraction 2 over 15 EndFraction
In other words,
b > 3 & 2/15
or
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Explanation:
Let's convert the mixed number 2 & 3/5 into an improper fraction.
We'll use the rule
a & b/c = (a*c + b)/c
In this case, a = 2, b = 3, c = 5
So,
a & b/c = (a*c + b)/c
2 & 3/5 = (2*5 + 3)/5
2 & 3/5 = (10 + 3)/5
2 & 3/5 = 13/5
The inequality is the same as
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Let's multiply both sides by 15 to clear out the fractions
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Now isolate the variable b
Side note: Another way to go from 47/15 to 3 & 2/15 is to notice how
47/15 = 3 remainder 2
The 3 is the whole part while 2 helps form the fractional part. The denominator stays at 15 the whole time.
check the picture below.
so the playground is really just 3 rectangles and one triangle, now the triangle has a base of 8 and a height of 6. We can simply get the area of each figure, sum them up and that's the area of the playground.
Given:
In a two-digit number, the tens digit is 5 less than the units digit.
The number itself is five more than three times the sum of its digits.
To find:
The number.
Solution:
Let the two digit number is ab. So,
Tens digit is 5 less than the units digit.
...(i)
The number itself is five more than three times the sum of its digits.
...(ii)
Using (i) and (ii), we get
Putting b=8 in (i), we get
Therefore, the required number is 38.