Answer:
Let n be the number of 25 cent stamps.Then, 28 - n must be the number of 29 cent stamps.Tim paid $7.60 the stamps.
0.25n + 0.29(28 - n) = 7.60
This means that n stamps at 25 cents a piece plus (28 - n) stamps at 29 cents a piece sum to $7.60.Solve for m.
0.25n + 8.12 - 0.29n = 7.60
-0.04n = -0.52
n = 13
So, Tim bought 13 25-cent stamps and 28 - 13 = 15 29-cent stamps
Step-by-step explanation:
hope this helps:)
The Arithmetic Mean and Median of the given set of data ( 2, 5, 13, 15, 19, 21 ) are 12.5 and 14 respectively.
<h3>What is Arithmetic mean?</h3>
Arithmetic mean is simply the average of a given set numbers. It is determined by dividing the sum of a given set number by their number of appearance.
Mean = Sum total of the number ÷ n
Where n is number of numbers
Median is the middle number in the data set.
Given the sets;
Mean = Sum total of the number ÷ n
Mean = (2 + 5 + 13 + 15 + 19 + 21) ÷ 6
Mean = 75 ÷ 6
Mean = 12.5
Median is the middle number in the data set.
Median = ( 13 + 15 ) ÷ 2
Median = 14
Therefore, the Arithmetic Mean and Median of the given set of data ( 2, 5, 13, 15, 19, 21 ) are 12.5 and 14 respectively.
Learn more about arithmetic mean here: brainly.com/question/13000783
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Answer:
A
Step-by-step explanation:
The velocity of a moving body is given by the equation:
Is the velocity is <em>positive </em>(v>0), then our object will be moving <em>forwards</em>.
And if the velocity is negative (v<0), then our object will be moving <em>backwards</em>.
We want to find between which interval(s) is the object moving backwards. Hence, the second condition. Therefore:
By substitution:
Solve. To do so, we can first solve for <em>t</em> and then test values. By factoring:
Zero Product Property:
Now, by testing values for t<1, 1<t<4, and t>4, we see that:
So, the (only) interval for which <em>v</em> is <0 is the second interval: 1<t<4.
Hence, our answer is A.
Answer:
20
Step-by-step explanation:
3 (b + a) = c
3 (4 + 5) = 7
12 + 15 = 7
27 = 7
27 - 7
20
