Statements #1-4 are all true. Statement 5 is false due to the fact that when x = 0, y = 3.
Answer:
Step-by-step explanation:
Let x represent the number of stamps from Europe.
Let y represent the number of stamps from Africa.
Let z represent the number of stamps from Asia.
She has 47 stamps in all. This means that
x + y + z = 47 - - - - - - - - - - - 1
The number of African stamps is 2 times the number of Asian stamps. This means that
y = 2z
She has 20 stamps from Europe. Therefore, substituting x = 20 and y = 2z into equation 1, it becomes
20 + 2z + z = 47
3z = 47 - 20 = 27
z = 27/3 = 9
y = 2z = 2 × 9
y = 18
She has 20 stamps from Europe, 18 stamps from Africa and 9 stamps Asia.
Answer:
a. 0.75
b. 0.5526
c. 0.1974
Step-by-step explanation:
Probability is typically expressed as a fraction where the numerator is the number of desired outcomes and the denominator is the total number of outcomes. In this case the suitable parts is the desired outcome and the total shipment is the total parts:

The probability the both the first and second part are suitable:

Since the probability of getting a suitable part the first time is 15/20, then there is one less suitable part and one less part overall to choose on the second time, or 14/19.
Lastly, the probability of choosing a suitable part the first time is again 15/20, but the second part not being suitable would be 5/19:
If xy=0 assume that at leas 1 is zero
set it to zero
0=2a^2-16a+32
undistribute 2
0=2(a^2-8a+16)
2*0=0 so assume
a^2-8a+16=0
factor
(a-4)(a-4)=0
set to zero
a-4=0
a=4
when a=4, equation equals zero