Ok so if 1200 total pens and 60 were taken that's a ratio of 1200/60=20
out of 60pens 4 didn't work, again ratio is 4/60=1/15 so about 1/15 of the pens didn't work.
so we have 1200pens * 1/15broken ratio = 80 pens or we can say
20*4=80pens won't work from 20 groups of 60 and 4 out of 60 not working is 20*4=80 not working from total batch of 1200.
hope this helps you some! thank you!!!!!!!!!
Answer:
Speed of plane in still air: 490 mile/hour
speed of wind: 70 mile/hour
Step-by-step explanation:
still speed = x wind speed = w
with wind: speed = still + wind
(x+w) * 3 = 1680 ...a
against wind: speed = still - wind
(x-w) * 4 = 1680 ...b
b-a ... 4x-4w-3x-3w = 0
x-7w = 0
x = 7w
substitution: (7w+w)*3 = 1680 8w = 560 wind speed (w) = 70
still speed (x) = 7w = 490 mile/hour
Answer:
Step-by-step explanation:
Suppose we think of an alphabet X to be the Event of the evidence.
Also, if Y be the Event of cheating; &
Y' be the Event of not involved in cheating
From the given information:



Thus, 
P(Y') = 1 - 0.01
P(Y') = 0.99
The probability of cheating & the evidence is present is = P(YX)



The probabilities of not involved in cheating & the evidence are present is:


(b)
The required probability that the evidence is present is:
P(YX or Y'X) = 0.006 + 0.000099
P(YX or Y'X) = 0.006099
(c)
The required probability that (S) cheat provided the evidence being present is:
Using Bayes Theorem



Answer:
9/4<x≤4 or all real numbers
Step-by-step explanation:
I'm not sure what you are asking