Một lô hàng gồm 1000 sản phẩm, trong đó có 10 phế phẩm. Lấy ngẫu nhiên ra 20 sản phẩm. Tìm xác suất để cho trong 20 sản phẩm lấy ra:
a) Có 5 phế phẩm;
b) Bị cả 10 phế phẩm;
c) Có đúng 5 chính phẩm.

the function makes a strait line horizontally with no x intercept but a y intercept at 9.

the answer is a) y= 2 csc [0.5 (x+pi/2)]-1

step-by-step explanation:

delaney would like to make a 5lb nut mixture that is 60% peanuts and 40% almonds.

she has several pounds of peanuts and several pounds of a mixture that is 20% peanuts and 80% almonds.

let 'p' represent the number of pounds of peanuts needed to make the new mixture, and  

let 'm' represent the number of pounds of the 80% almond-20% peanut mixture.

:

p + m = 5

therefore

m = (5-p)

write an equation based on the percent of peanuts

1p + .2m = .6(5)

replace m with (5-p)

p + .2(5-p) = .6(5)

p + 1 - .2p = 3

p - .2p = 3 - 1

.8p = 2

p = 2/.8

p = 2.5 lbs of peanuts required

then

5 - 2.5 = 2.5 lbs of the peanut/almond mixture required

:

a) what is the system that models this situation?

p + m = 5

1p + .2m = .6(5)