Answer:
a. Alice
b. Briana
c. 0.51 minutes
Step-by-step explanation:
a. Alice formula is valid for any t > 0 minutes, but Briana formula is only valid for
2t - 1 > 0
2t > 1
t > 1/2 minutes
b. They finish when their covered distance is equal to 5 kilometers. For Alice:
t/4 = 5
t = 5*4 = 20 minutes
For Briana:
√(2t - 1) = 5
2t - 1 = 5²
2t = 25 + 1
t = 26/2
t = 13 minutes
c. They are side by side when they have covered the same distance, that is:
t/4 = √(2t - 1)
(t/4)² = 2t - 1
t²/16 = 2t - 1
t² = 16*(2t - 1)
t² = 32t - 16
t² - 32t + 16 = 0
Using quadratic formula:







Only the second answer has sense for this problem because the race already finished before they spent 31.49 minutes in it.
Answer:
The probability that it will take more than 10 minutes for the next student to arrive at the library parking lot is 0.0821.
Step-by-step explanation:
The random variable <em>X</em> is defined as the amount of time until the next student will arrive in the library parking lot at the university.
The random variable <em>X</em> follows an Exponential distribution with mean, <em>μ</em> = 4 minutes.
The probability density function of <em>X</em> is:

The parameter of the exponential distribution is:

Compute the value of P (X > 10) as follows:


Thus, the probability that it will take more than 10 minutes for the next student to arrive at the library parking lot is 0.0821.
X liters of 10% + (30 - x) liters of 22% = 30 liters of 15%
<span>Plugging in the numbers </span>
<span>x(10) + (30 - x)22 = 30(15) </span>
<span>Distribute </span>
<span>10x + 660 - 22x = 450 </span>
<span>Combine like terms </span>
<span>-12x = -210 </span>
<span>Divide both sides by -12 </span>
<span>x = 17.5 </span>
<span>30 - x = 12.5 </span>
<span>17.5 liters of 10% + 12.5 liters of 22% = 30 liters of 15%
THE TRICK IS TO JUST USE ONLY ONE VARIABLE</span>
The average speed of train:
12,000 km / ( 28 + 22 hr) =12,000 km / 50 hr = 240 km/hr
Answer: D)
Answer:
The average price of a gallon of orange increased by $0.03 each month.
Step-by-step explanation:
It is 11 months between October 2013 and September 2014 so the price after 11 months =
f(11) = 6.12 + 0.03(11)
= 6.12 + 0.33
= $6.45.
This is an increase of 0.33 / 11 = 0.03 / month.