How many days is 45% of 31 days

The minute hand rotates once around the clock every hour. It goes 360 degrees in 60 minutes, so it rotates 360/60 or 6 degrees per minute. The hour hand goes once around the clock every 12 hours. Because there are 60 minutes in an hour, it goes 360 degrees 12*60 or 720 minutes. This means it travels at a speed of 360/720 or 0.5 degrees per minute.

Once the clock starts, the minute hand goes ahead and rotates ahead of the hour hand. At 1:00, the minute hand is at 12, and the hour hand is ahead at 1. This is where we will start our calculations.

Now, we have a variable, m, which is the minutes that have passed since the clock started. So, our minute hand speed is 6m, and our hour hand speed is 0.5m. However, because the hour hand is at one, it is at 30 degrees. (360/12 * 1.) This means our equation is 6m = 0.5m+30.

Now, we calculate.

6m = 0.5m+30

5.5m = 30

m = 30/5.5

m = 5.45

So at 5.45 minutes, the minute hand is at the hour hand. However, because one hour has passed since we started, we have to add on one hour.

So, our final total is 1 hour 5 minutes and 27 seconds.

Step-by-step explanation:

4 0

3 years ago

In a certain clinical study, 15% of participants were classified as heavy smokers, 25% as light-smokers, and the rest as non-smo

Natasha_Volkova [10]

Answer:

There is a 28.57% probability that a randomly selected participant who died by the end of the study was a non-smoker.

Step-by-step explanation:

We have the following probabilities:

A 15% probability that a participant is classified as a heavy smoker.

A 25% probability that a participant is classified as a light smoker.

A 100% - 25% - 15% = 60% probability that a participant is classified as a non smoker.

A x% probability that a non smoker dies.

A 3x% probability that a light smoker dies.

A 5x% probability that a heavy smoker dies.

This can be formulated as the following problem:

What is the probability of B happening, knowing that A has happened.

It can be calculated by the following formula

$P = \frac{P(B).P(A/B)}{P(A)}$

Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.

This problem is:

What is the probability of the participant being a non-smoker, given that he died?

P(B) is the probability that the participant is a non smoker. So

$P(B) = 0.6$

P(A/B) is the probability that the participant dies, given that he is a non smoker. So:

$P(A/B) = x$

P(A) is the probability that the participant dies:

$P(A) = P_{1} + P_{2} + P_{3}$

$P_{1}$ is the probability that a heavy smoker is selected and that he dies. So:

$P_{1} = 0.15*5x = 0.75x$

$P_{2}$ is the probability that a light smoker is selected and that he dies. So:

$P_{2} = 0.25*3x = 0.75x$

$P_{3}$ is the probability that a non-smoker is selected and that he dies. So:

$P_{3} = 0.60*x = 0.60x$

The probability that a participant dies is:

$P(A) = P_{1} + P_{2} + P_{3} = 0.75x + 0.75x + 0.60x = 2.10x$

The probability of the participant being a non-smoker, given that he died, is:

$P = \frac{P(B).P(A/B)}{P(A)} = \frac{0.6x}{2.10x} = \frac{0.6}{2.10} = 0.2857$

There is a 28.57% probability that a randomly selected participant who died by the end of the study was a non-smoker.

7 0

3 years ago