The average score of all the students in both classes is 84.
<h3>How to calculate the average?</h3>
The class with 30 students had an average score of 80 on a test. The total score will be:
= 30 × 80
= 2400
A class with 20 students had an average score of 90 on the same test. The total score will be:
= 20 × 90
= 1800
Total scores = 2400 + 1800 = 4200
Number of students = 20 + 30 = 50
The average score will be:
= Total score / Total students
= 4200 / 50
= 84
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By definition of percentages, we conclude that Montraie has 10 coins saved in his box that come from a collection with a total of 50 coins.
<h3>How to calculate the quantity of coins in a collection</h3>
In this question we know the quantity of coins in a box and such coins are part of the <em>coin</em> collection. By definition of percentage we have the <em>total</em> quantity of coins in the collection:
x = 10*(100/20)
x = 50
By definition of percentages, we conclude that Montraie has 10 coins saved in his box that come from a collection with a total of 50 coins.
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She can travel <span>665.4375 miles in 68.25 min.</span>
13. 1,6
18. -15,12
19. -7, 1/2
Given:
A line passes through the points (2,-1) and (1,-5).
To find:
The equation of the line.
Solution:
If a line passes through the two points, then the equation of the line is
The line passes through the points (2,-1) and (1,-5). So, the equation of the line is
Using distributive property, we get
Subtract 1 from both sides.
Therefore, the correct option is B.
