Answer: 0.27648
Step-by-step explanation:
Given : The proportion of all individuals have group A blood : p=0.040
Total individuals give blood : n= 6
Let X be the number of individuals have group A blood.
Since all individual are independent of each other.

Formula :
, where n= sample size , p = probability of getting success in each trial.
The probability that exactly three of the individuals have group A blood. :

The probability that exactly three of the individuals have group A blood. is 0.27648
Mrs. Annie went to a store, spent half of her money and then $10 more. She went to a second store, spent half of her remaining money and then $10 more. But she then had no money left. How much money did she have to begin with when she went to the first store?
Answer: $60
Answer:
x = -1 and y = 18
Step-by-step explanation:
Given the system of equations
y + 8x = 10... 1
2y - 4x = 40 ... 2
From 1; y = 10-8x
Substitute into 2;
2(10-8x) - 4x = 40
20 - 16x - 4x = 40
20 - 20x = 40
-20x = 40 - 20
-20x = 20
x = -1
Recall that y = 10-8x
y = 10 - 8(-1)
y = 10 + 8
y = 18
therefore your answer is x = -1 and y = 18