Answer:
Percentage of balls which are red = 80%.
Step-by-step explanation:
Let the probability of drawing a red ball be x then the probability of drawing a white ball is 1-x.
There are 5C3 = 10 ways of getting 3 reds in 5 draws so the probability of this is 10* x^3 * (1 - x)^2.
The probability of getting 1 red in 5 draws = 5C1 * x (1-x)^4.
The first probability is 32 times the last.
So we have the equation:
10x^3(1 - x)^2 / 5x(1 - x)^4 = 32
2x^2 / (1 - x)^2 = 32
2x^2 = 32(1 -x)^2
2x^2 = 32( 1 - 2x + x^2)
2x^2 = 32 - 64x + 32x^2
30x^2 - 64x + 32 = 0
15x^2 - 32x + 16 = 0
(5x - 4)(3x - 4) = 0
x = 0.8, 1.333...
The probability must be < 1 so x = 0.8 = 80%.
Answer:
A.s<30
Step-by-step explanation:
We are given that
Number of students who ride in a bus=s
We have to find the inequality which represents the given situation.
According to question
s<30
A.s<30
It is true.
B.s>30
It is false because s is less than 30
C.
It is false because s<30
D.
It is false because s<30
Option A is true.
6
Step-by-step explanation:
-2^3=-8
-10+(-8)=-10-8=-18
-18÷-3=6
