Answer:
0.75
Step-by-step explanation:
Given,
P(A) = 0.6, P(B) = 0.4, P(C) = 0.2,
P(A ∩ B) = 0.3, P(A ∩ C) = 0.12, P(B ∩ C) = 0.1 and P(A ∩ B ∩ C) = 0.07,
Where,
A = event that the selected student has a Visa card,
B = event that the selected student has a MasterCard,
C = event that the selected student has an American Express card,
We know that,
P(A ∪ B ∪ C) = P(A) + P(B) + P(C) - P(A ∩ B) - P(A ∩ C) - P(B ∩ C) + P(A ∩ B ∩ C)
= 0.6 + 0.4 + 0.2 - 0.3 - 0.12 - 0.1 + 0.07
= 0.75
Hence, the probability that the selected student has at least one of the three types of cards is 0.75.
Answer:
B= 15 adults tickets
C= 35 student tickets
Step-by-step explanation:
x+y=50
solve for y
y=50-x
5x+3y=180
5x+3(50-x)=180
5x+150-3x=180
2x=30
x=15
y=50-15
y=35
A direct variation is a mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other. In other words, a direct variation is where

.
In answer a,

, so it is a direct variation.
In answer c,

, so it is a direct variation.
In answer d,

, so it is a direct variation,
Only answer b is left, which means the answer must be 'b'.
We also know 'b' is the answer because it cannot be expressed as <span>

. Instead, it is expressed as </span>

, which is not the same thing and is therefore not a direct variation.
Hope I helped, and let me know if you have any questions :)