Answer:
0.4546
Step-by-step explanation:
nCr = n!/(n-r)!r!
Number of ways of selecting the four defective voltage regulators from 12 = 12C4 = 12!/(12-4)!4! = 12!/8!4! = (12 *11*10*9)/(4*3*2*1)
12C4 = 495 ways
Number of ways of selecting 2 defectives from line 1 = 6C2 * 6C2
6C2 = 6!/(6-2)!2! = 6!/4!2! = (6*5)/(2*1) = 15
6C2 * 6C2 = 15*15 = 225 ways
Probability = Number of possible outcomes/ Number of total outcomes
Probability that exactly 2 of the defective regulators came from line 1 = 225/40.95 = 0.4546
Just "plug n chug" as my teacher would say. In other words, replace the letters with the values.
Choice A is (7,19) which means x = 7 and y = 19. Let's replace the x and y value with these numbers in both equations. If we get a true equation, then we found the answer.
2x-y = -5
2*7-19 = -5
14-19 = -5
-5 = -5 ... true
So that works. Let's try the other equation
x+3y = 22
7+3*19 = 22
7+57 = 22
64 = 22 ... false
So choice A is NOT the answer because of this. Let's try out choice B
2x-y = -5
2*4-9 = -5
-1 = -5 ... false
so B doesn't work either. How about C?
2x-y = -5
2*8-21 = -5
-5 = -5 ... that works
x+3y = 22
8+3*21 = 22
71 = 22 ... but this is false
So D has to be the answer. Let's check to confirm or not
2x-y = -5
2*1-7 = -5
-5 = -5 ... true
x+3y = 22
1+3*7 = 22
22 = 22 ... true
BOTH equations are true at the same time so (1,7) is definitely the final answer
Answer is in the file below
tinyurl.com/wpazsebu
Right triangle
1) 75.6cm
2)10.14ft
3)16ft
Entire triangle
1)162cm
2)30.94ft
3)20ft
