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.
Answer:
The ultra-marathon Idita Rod Trail is about 38 times longer than the Boston Marathon.
Step-by-step explanation:
Let
x -----> the length of the Boston Marathon in meters
y -----> the length of the Idita rod Trail Invitational ultra-marathon in meters
we have


we know that
To find out how many times as long is the course of the Idita rod Trail ultra-marathon as that of the Boston Marathon, divide the length of the Idita rod Trail Invitational ultra-marathon by the length of the Boston Marathon
so


Remember that
To divide two numbers in scientific notation, divide their coefficients and subtract their exponents

therefore
The ultra-marathon Idita Rod Trail is about 38 times longer than the Boston Marathon.
Answer:
The concentration of salt in the tank approaches
Step-by-step explanation:
Data provide in the question:
Water contained in the tank = 8000 L
Salt per litre contained in Brine = 35 g/L
Rate of pumping water into the tank = 25 L/min
Concentration of salt 
Now,
Dividing both numerator and denominator by
, we have

Here,
The concentration of salt in the tank approaches
At first, Anita looks like her account would grow faster. By month 4, shes at $1,200 while Miguel is at $400. However, Anita is only getting $200 a month. While Miguel gets double of whatever amount he has in his bank account. By month 10, Anita is at $2,400 while Miguel has $25,600. That is a $23,200 difference. So Miguel's bank account will grow faster than Anita.
Given : tan 235 = 2 tan 20 + tan 215
To Find : prove that
Solution:
tan 235 = 2 tan 20 + tan 215
Tan x = Tan (180 + x)
tan 235 = tan ( 180 + 55) = tan55
tan 215 = tan (180 + 35) = tan 35
=> tan 55 = 2tan 20 + tan 35
55 = 20 + 35
=> 20 = 55 - 35
taking Tan both sides
=> Tan 20 = Tan ( 55 - 35)
=> Tan 20 = (Tan55 - Tan35) /(1 + Tan55 . Tan35)
Tan35 = Cot55 = 1/tan55 => Tan55 . Tan35 =1
=> Tan 20 = (Tan 55 - Tan 35) /(1 + 1)
=> Tan 20 = (Tan 55 - Tan 35) /2
=> 2 Tan 20 = Tan 55 - Tan 35
=> 2 Tan 20 + Tan 35 = Tan 55
=> tan 55 = 2tan 20 + tan 35
=> tan 235 = 2tan 20 + tan 215
QED
Hence Proved