Answer:
2.4 hours
Step-by-step explanation:
Let total work = X
Rate of work done = X ÷ time
Rate of A = X/4
Rate of B = X/6
If they work together, rate is the sum of their individual rates, i.e.
X/4 + X/6
= (3X + 2X)/12 (taking LCM)
=5X/12
Rate = X/time
5X/12 = X/time
time = X÷(5X/12)
time = X × 12/(5X)
time = 2.4 hours
Shortcut:
Product of individual times/sum of individual times
= (4×6)/(4+6)
=24/10
=2.4 hours
(553-265)/48=6
6 hours spent repairing the car
Using the binomial distribution, it is found that the probability that at least 12 of the 13 adults require eyesight correction is of 0.163 = 16.3%. Since this probability is greater than 5%, it is found that 12 is not a significantly high number of adults requiring eyesight correction.
For each person, there are only two possible outcomes, either they need correction for their eyesight, or they do not. The probability of a person needing correction is independent of any other person, hence, the binomial distribution is used to solve this question.
<h3>What is the binomial distribution formula?</h3>
The formula is:


The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- A survey showed that 77% of us need correction, hence p = 0.77.
- 13 adults are randomly selected, hence n = 13.
The probability that at least 12 of them need correction for their eyesight is given by:

In which:



Then:

The probability that at least 12 of the 13 adults require eyesight correction is of 0.163 = 16.3%. Since this probability is greater than 5%, it is found that 12 is not a significantly high number of adults requiring eyesight correction.
More can be learned about the binomial distribution at brainly.com/question/24863377
Answer:
C. -9
Step-by-step explanation:
The pattern is clearly subtracting 4 each time (or adding -4).
-5 - 4 = -9
Answer:01 50 Hrs
Step-by-step explanation:
If the soldier started patrol at 2230 hrs and his petrol lasted for 3 hours and 20 minutes, that means he was on patrol for that time.
The time he finished was therefore:
= 2230 + 320
= 2550
At 24 you begin at 0:00am so:
= 2550 - 2400
= 150
Patrol ended at 0150 hrs