PLEASE EXPLAIN! THANK YOU!

SashulF [63]

Answer:

3.2 km/h

Step-by-step explanation:

1. Approach

The average speed is the rate at which one travels. It can be found by diving the total distance traveled over the total time it took to cover that distance. In essence, the following formula can be used to find the average speed:

$\frac{total\ distance}{total\ time}=average\ speed$

In this situation, one is asked to find the difference between two people's average speed. One is given the following information:

Lena: 24 miles 1.5 hours

Ras: 36km 1 hour 15 minutes

First, convert all of the numbers into the correct units (km) and (hours). Then find the average speed for each person. Finally, subtract the smaller speed from the larger speed to find the difference in the average speeds.

1. Find Lena's average speed

The problem asks one to find the average speed in the units (km/h). However, the distance Lena covered is given in (miles). Therefore, one has to multiply it by the conversion factor (1.6) in order to convert it from (miles) to (km).

24miles * 1.6 = 38.4

Now find the average speed by using the formula:

$\frac{total\ distance}{total\ time}=average\ speed$

Substitute,

$\frac{38.4}{1.5}\\\\=25.6$

2. Find Ras's average speed

Use a similar approach to work out Ras's average speed, as was used to find Lena's average speed. Since Ras's time spent is given in both hours and minutes, one must convert it to just minutes. There are (60) minutes in an hour, thus, one can rewrite the number as the following:

$1\ hour \ \ 15\ minutes= 1 \frac{15}{60}\ hours = \frac{75}{60}\ hours$

Now find the average speed:

$\frac{total\ distance}{total\ time}=average\ speed$

Substitute,

$\frac{36}{\frac{75}{60}}\\\\=28.8$

3. Find the difference between the speeds

Since Ras's speed is greater, subtract Lena's speed from Ras's speed.

Ras - Lena

= 28.8 - 25.6

= 3.2

6 0

3 years ago

Po is an oncologist with seven patients in their care. the probability that a patient will survive five years after being diagno

alekssr [168]

Answer:

0.0923 = 9.23% probability that four of the patients are still alive after five years.

Step-by-step explanation:

For each patient, there are only two possible outcomes. Either they are still alive after five years, or they are not. The probability of a patient being alive is independent of any other patient, which means that the binomial probability distribution is used 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.

Po is an oncologist with seven patients in their care.

This means that $n = 7$

The probability that a patient will survive five years after being diagnosed with stage three breast cancer is 0.82.

This means that $p = 0.82$

What is the probability that four of the patients are still alive after five years?

This is P(X = 4). So

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

$P(X = 4) = C_{7,4}.(0.82)^{4}.(0.18)^{3} = 0.0923$

0.0923 = 9.23% probability that four of the patients are still alive after five years.

5 0

3 years ago

Consider the diagram. The congruence theorem that can be used to prove △BAE ≅ △CAD is SSS. ASA. SAS. HL.

vesna_86 [32]

I think the answer is d

6 0

4 years ago

Read 2 more answers

I need help with 2 and 3<br> Please help :)

Alecsey [184]

2.) 15+45 = 60

3.) 9+27 = 36

7 0

3 years ago

It costs $100 to rent the bowling alley, plus $4 per person. The cost for any number (n) of people can be found using the expres

d1i1m1o1n [39]

Answer:

It would cost $160 for 15 people to rent the bowling alley

Step-by-step explanation:

First, let's identify what we know:

1) It costs $100, just to rent the bowling alley.

2) We have to add $4 dollars, for every extra person.

3) The total cost can be found by using the expression 100 + 4n = x (n equals number of people, x equals total cost, 100 equals intial rent charge, and 4 equals the charge for each individual person)

So, just input 15 into the equation!

100 + 4(15) = x

100 + 60 = x

x = $160

7 0

3 years ago