Ask question

Ask question

All categories

3 years ago

10

12. Nancy walked 516 yards in 6 minutes and then another 368 yards in 4 minutes. What was Nancy's average speed? * A. 89 yd/min

B. 89.4 yd/min C. 88.4 yd/min D. 178 yd/min

2 answers:

spayn [35]3 years ago

8 0

Hello.

The answer would be <span>C. 88.4.

You have to add the total distance (yards) and then divide it by the total time (minutes).

So you would divide 8</span>84 yards by 10 minutes to get 88.4

Have a ncie day

dybincka [34]3 years ago

4 0

Average speed = (total distance covered) / (time to cover the distance)

total distance covered = (516 + 368) = 884 yards
time to cover the distance = (6 + 4) = 10 minutes

Average speed = (884 yards) / (10 minutes) = 88.4 yds/min (C)

You might be interested in

In 2010, the population of a city was 161,000. From 2010 to 2015, the population grew by 8%. From 2015 to 2020, it fell by 6.7%.

solniwko [45]

Answer:

99%

Step-by-step explanation:

2010 population = 161,000

From 2010 to 2015, the population grew by 8%.

2010 to 2015 = 161,000 + (8% of 161,000)

= 161,000 + (0.08 * 161,000)

= 161,000 + 12,880

= 173,880

2010 to 2015 = 173,880

From 2015 to 2020, it fell by 6.7%

2015 to 2020 = 173,880 - (6.7% of 173,880)

= 173,880 - (0.067 * 173,880)

= 173,880 - 11,649.96

= 162,230.04

2015 to 2020 = 162,230.04

what percent did the city grow from 2010 to 2020.

= 161,000 / 162,230.04 × 100

= 0.9924179270374 × 100

= 99.241792703743

Approximately, 99% to the nearest whole number

4 0

2 years ago

Richard has just been given an l0-question multiple-choice quiz in his history class. Each question has five answers, of which o

myrzilka [38]

Answer:

a) 0.0000001024 probability that he will answer all questions correctly.

b) 0.1074 = 10.74% probability that he will answer all questions incorrectly

c) 0.8926 = 89.26% probability that he will answer at least one of the questions correctly.

d) 0.0328 = 3.28% probability that Richard will answer at least half the questions correctly

Step-by-step explanation:

For each question, there are only two possible outcomes. Either he answers it correctly, or he does not. The probability of answering a question correctly is independent of any other question. This means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

Each question has five answers, of which only one is correct

This means that the probability of correctly answering a question guessing is $p = \frac{1}{5} = 0.2$

10 questions.

This means that $n = 10$

A) What is the probability that he will answer all questions correctly?

This is $P(X = 10)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} = 0.0000001024$

0.0000001024 probability that he will answer all questions correctly.

B) What is the probability that he will answer all questions incorrectly?

None correctly, so $P(X = 0)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{10,0}.(0.2)^{0}.(0.8)^{10} = 0.1074$

0.1074 = 10.74% probability that he will answer all questions incorrectly

C) What is the probability that he will answer at least one of the questions correctly?

This is

$P(X \geq 1) = 1 - P(X = 0)$

Since $P(X = 0) = 0.1074$ , from item b.

$P(X \geq 1) = 1 - 0.1074 = 0.8926$

0.8926 = 89.26% probability that he will answer at least one of the questions correctly.

D) What is the probability that Richard will answer at least half the questions correctly?

This is

$P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 5) = C_{10,5}.(0.2)^{5}.(0.8)^{5} = 0.0264$

$P(X = 6) = C_{10,6}.(0.2)^{6}.(0.8)^{4} = 0.0055$

$P(X = 7) = C_{10,7}.(0.2)^{7}.(0.8)^{3} = 0.0008$

$P(X = 8) = C_{10,8}.(0.2)^{8}.(0.8)^{2} = 0.0001$

$P(X = 9) = C_{10,9}.(0.2)^{9}.(0.8)^{1} \approx 0$

$P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} \approx 0$

So

$P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0264 + 0.0055 + 0.0008 + 0.0001 + 0 + 0 = 0.0328$

0.0328 = 3.28% probability that Richard will answer at least half the questions correctly

8 0

3 years ago

If you place a 10-foot ladder against the top of a 6-foot building, how many feet will the bottom of the ladder be from the bott

Anika [276]

Answer: 8 feet

Step-by-step explanation:

Draw a right triangle and label the sides using the given information. (Drawing below) Use pythagorean theorem to find the missing length:

a^2 + b^2 = c^2

(building)^2 + (missing piece)^2 = (ladder)^2

6^2 + x^2 = 10^2

36 + x^2 = 100. subtract 36

x^2 = 64. square root of both sides

x = 8

6 0

3 years ago

A stock-car race lasted 2.07 hours. how many seconds did the race last?

kolezko [41]

$2.07 hr x \frac{60 min}{1 hr} x \frac{60 sec}{1 min} = 7452 sec$

8 0

3 years ago

38 plus what equals 99

mote1985 [20]

To figure that out you could do 99 minus 38, which would lead you to your answer 61.

7 0

3 years ago