Anna has a collection of 45 nickels and quarters worth $8.05. How many nickets does she have?
1 answer:
Anna has 16 nickels
<em><u>Solution:</u></em>
Let "n" be the number of nickels
Let "q" be the number of quarters
We know that,
1 nickel = $ 0.05 or 5 cent
1 quarter = $ 0.25 or 25 cent
<em><u>Anna has a collection of 45 nickels and quarters</u></em>
Therefore,
n + q = 45
q = 45 - n --------- eqn 1
<em><u>Anna has a collection of 45 nickels and quarters worth $8.05</u></em>
$ 8.05 is worth 805 cents
Thus we frame a equation as:
number of nickels x 5 cents + number of quarters x 25 cents = 805
5n + 25q = 805 ----- eqn 2
<em><u>Let us solve eqn 1 and eqn 2</u></em>
<em><u>Substitute eqn 1 in eqn 2</u></em>
5n + 25(45 - n) = 805
5n + 1125 - 25n = 805
20n = 1125 - 805
20n = 320
n = 16
Thus Anna has 16 nickels
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88.88% probability that it endures for less than a year and a half
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean and standard deviation
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The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
The next career begins on Monday; what is the likelihood that it endures for less than a year and a half?
One year has 52.14 weeks. So a year and a half has 1.5*52.14 = 78.21 weeks.
So this probability is the pvalue of Z when X = 78.21.
has a pvalue of 0.8888
88.88% probability that it endures for less than a year and a half