The answer is <span>twelve sevenths (12/7)
</span>
x - the job<span>
t - time to do the job x
</span><span>Robin can mow a lawn in 3 hours: x/3 * t
</span><span>Brady can mow the same lawn in 4 hours: x/4 * t
</span><span>If they work together, the total work will
be the sum of their speeds:
</span>x = x/3 * t + x/4 * t = (x/3 + x/4)*t = (4x/12 + 3x/12) * t = 7x/12 * t
x = 7x/12 * t
Divide both sides by x:
x/x = 7x/12 * t/x
1 = 7/12 t
t = 1 : 7/12
t = 12/7
Answer: D
Step-by-step explanation:
C=πd=π·22≈69.11504m :)
Answer: the 1st one.
Step-by-step explanation: becuase today I was helping out a freind with this. So it the first one
Answer:−3K−395,−374,−198,−187
Step-by-step explanation:
Remove parentheses.
1−3K−396,0−374,0−198,0−187
Simplify 1-3K-3961−3K−396 to -3K-395−3K−395.
−3K−395,0−374,0−198,0−187
Simplify 0-3740−374 to -374−374.
−3K−395,−374,0−198,0−187
Simplify 0-1980−198 to -198−198.
−3K−395,−374,−198,0−187
Simplify 0-1870−187 to -187−187.
−3K−395,−374,−198,−187
Answer:
a) 8*88*10⁻⁶ ( 0.00088 %)
b) 0.2137 (21.37%)
Step-by-step explanation:
if the test contains 25 questions and each questions is independent of the others, then the random variable X= answer "x" questions correctly , has a binomial probability distribution. Then
P(X=x)= n!/((n-x)!*x!)*p^x*(1-p)^(n-x)
where
n= total number of questions= 25
p= probability of getting a question right = 1/4
then
a) P(x=n) = p^n = (1/4)²⁵ = 8*88*10⁻⁶ ( 0.00088 %)
b) P(x<5)= F(5)
where F(x) is the cumulative binomial probability distribution- Then from tables
P(x<5)= F(5)= 0.2137 (21.37%)
