Averages — Quiz 3

Questions in this quiz (9)

1. Maya has 8 equally weighted quizzes in her History class. If she has a 85 average on the first 6 quizzes, what must she average on the last 2 quizzes to achieve an overall average of 90 in the class?

   • 95
   • 100
   • 90
   • 105

2. If $$m$$ students scored an average of $$c$$ on a Statistics exam and $$n$$ students scored an average of $$d$$, what is the expression for the overall average of all $$m+n$$ students?

   • $$\frac{mc+nd}{c}$$
   • $$\frac{c+d}{m+n}$$
   • $$\frac{mc+nd}{m+n}$$
   • $$\frac{mc+nd}{dc}$$

3. If the final exam counted for $$25%$$ of Alex's Chemistry grade, his grade before the final was $$p$$ and his final grade for the class was $$s$$. What score did Alex achieve on the final in terms of $$p$$ and $$s$$?

   • $$4s - 3p$$
   • $$s - 3p$$
   • $$0.75s - 3p$$
   • $$4s - 0.75p$$

4. If 10 students scored an average of 85 on a biology test and the overall average for the entire class of 25 students was 75, what is the average score of the other 15 students?

   • 68.33
   • 75.00
   • 65.00
   • 60.50

5. The average of $$x$$ and $$t$$ is $$y$$. If $$s=3y$$, what is the average of $$s$$, $$x$$, and $$t$$ in terms of $$y$$?

   • $$\frac{y}{3}$$
   • $$\frac{4y}{3}$$
   • $$\frac{5y}{3}$$
   • $$\frac{3y}{5}$$

6. Jessica and Josh want an average score of 95 for five exams. Jessica’s scores are 93, 92, 90, and 100. Josh’s scores are 95, 97, 89, and 94. For each student to average a 95 for the five exams, how many more points does Josh need to get than Jessica on the last test?

   • 5
   • 10
   • 7
   • 0

7. A cyclist rides 30 miles to a park at a speed of 50 miles per hour and returns home at a speed of 30 miles per hour. What is the cyclist’s average speed for the entire round trip, in miles per hour?

   • 40
   • 37.5
   • 35
   • 45

8. Lena drives on two types of roads during her commute. She averages 50 miles per hour on rural roads and 60 miles per hour on the highway. Lena’s total drive includes twice as many highway miles as rural road miles. If she drives a total of 540 miles, what is her average speed for the entire trip? Round your answer to the nearest whole number.

   • 60
   • 56
   • 50
   • 54

9. A certain food truck sells burritos and tacos. Burritos cost $$5$$ and tacos cost $$2$$. Last year the truck had a total of $$15$$ items on the menu and the average price of an item was $$3$$. This year it added more taco items and the average price of a food item dropped to $$2.50$$. How many taco items are on the menu now?

   • 25
   • 15
   • 10
   • 45