Answer:
$45
Step-by-step explanation:
The sale price changed from $80 to 60, then with the coupon another 25% was taken off leading it to come to a price of $45
$80 x .75 = 60
$60 x .75 = 45
(.75 is for the price of the original value that he will be paying later)
It depends if the 12 spice jars are all different.
If they are:
_ _ _ _ _ _ _ _ _ (9 spaces)
12*11*10*9*8*7*6*5*4
12 possibilities for first one, 11 for second, etc...
Multiply out to get:
79833600
It would be 100. Because let's say you had to round 25 to the nearest 10 it would be 30 because everything ending with 5 (example: 5 to nearest 10 would go to 10 65 to the nearest ten would go to 70) but anything lower then 5 goes to the lower number.
We can use the binomial theorem to find the probability that 0 out of the 15 samples will be defective, given that 20% are defective.
P(0/15) = (15C0) (0.2)^0 (1 - 0.2)^15 = (1)(1)(0.8)^15 = 0.0352
Then the probability that at least 1 is defective is equal to 1 - 0.0352 = 0.9648. This means there is a 96.48% chance that at least 1 of the 15 samples will be found defective. This is probably sufficient, though it depends on her significance level. If the usual 95% is used, then this is enough.
Y = mx + c
y = 2x + c
When x = 5 and y = 0,
0 = 2(5) + c
c = -10
y = 2x - 10
