-243
Step-by-step explanation:
số dương nhân -3 thì đc số âm, số âm nhân với -3 để đc số dương.
vd: 1. -3 = -3 ; -3 .-3= 9 ;..... 81 . -3= -243
Anw:
a
Step-by-step explanation:
72*4=5x
=288
5x=288
x=288/5
=57.6
x=57.6
57.6/72=0.8
4/5=0.8
Answer:
21 squared
Step-by-step explanation:
this is because you add together 9 and 12. this gives you 21 and because you want it squared it would be 21 squared.
4? Are you doing a survey or poll or just collecting results?
Answer:
Given two events A and B of a sample set :-
P[A] = 0.20
P[not B]=0.40
![P[B/A]=0.25](https://tex.z-dn.net/?f=P%5BB%2FA%5D%3D0.25)
To find P[A or B]:
![P[A or B] = P[A] + P[B] - P[A \cap B]](https://tex.z-dn.net/?f=P%5BA%20or%20B%5D%20%3D%20P%5BA%5D%20%2B%20P%5BB%5D%20-%20P%5BA%20%5Ccap%20B%5D)
......[1]
Calculate for ![P[B]](https://tex.z-dn.net/?f=P%5BB%5D)
and ![P[A \cap B]](https://tex.z-dn.net/?f=P%5BA%20%5Ccap%20B%5D)
P[B] = 1- P[not B]
Substitute the value P[not B] we get;
P[B] = 1-0.40 = 0.60
![P[A \cap B] = P[B/A] \cdot P[A]](https://tex.z-dn.net/?f=P%5BA%20%5Ccap%20B%5D%20%3D%20P%5BB%2FA%5D%20%5Ccdot%20P%5BA%5D)
Substitute the given values we get;
![P[A \cap B] = 0.25 \cdot 0.20 = 0.05](https://tex.z-dn.net/?f=P%5BA%20%5Ccap%20B%5D%20%3D%200.25%20%5Ccdot%200.20%20%3D%200.05)
Then;
![P[A or B] = 0.20+0.60-0.05 = 0.80-0.05 =0.75](https://tex.z-dn.net/?f=P%5BA%20or%20B%5D%20%3D%200.20%2B0.60-0.05%20%3D%200.80-0.05%20%3D0.75)
Therefore, the value of P[A or B] is, 0.75.
