Let the number of sodas sold be x and the number of hotdogs sold be y. We can assemble a system of equations from the information given and solve.
x+y=170 (We know that soda + dogs is 170)
x-50=y (We know that dogs is equal to 50 less than sodas)
We can use substitution to solve this system of equations.
x+y=170
Sub in the value of y from the second equation
x+(x-50)=170
2x-50=170
2x=220
x=110
We now know the number of sodas sold was 110. Lets now plug this value into the equation to solve for y.
x+y=170
110+y=170
y=60
So, there were 60 hotdogs sold and 110 sodas sold.
1. 2 3/4 = 11/4(2 * 4 + 3)
2. 1 1/4 = 5/4(1 * 4 + 1)
11/4 * 5/4 = 55/16 OR 3 7/16 if simplified.
The sample is his friends. They might be the same group of interests. The sample needs to be random. Even if he went around and grabbed random people he may not have known at his school, it still wouldn't be random bc they could all be bias towards a local sports team or have different interests than someone from somewhere else
Answer:
0.0545 = 5.45% probability that exactly seven are retired people.
Step-by-step explanation:
For each stock investor, there are only two possible outcomes. Either they are retired people, or they are not. Stock investors are independent. This means that we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which 
is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
20% of all stock investors are retired people.
This means that 
a. What is the probability that exactly seven are retired people?
0.0545 = 5.45% probability that exactly seven are retired people.
Answer: 22 small snow cones and 34 large snow cones were sold.
Step-by-step explanation:
Let x represent the number of small snow cones that were sold.
Let y represent the number of large snow cones that were sold.
Selena's snow cone stand sells small snow cones for $2 and large snow cones for $3.50. One summer day, she sold $163 worth of snow cones. This means that
2x + 3.5y = 163 - - - - - - - - - - 1
If the number of large snow cones sold was 12 more than the number of smalls snow cones, it means that
y = x + 12
Substituting y = x + 12 into equation 1, it becomes
2x + 3.5(x + 12) = 163
2x + 3.5x + 42 = 163
5.5x = 163 - 42
5.5x = 121
x = 121/.5 = 22
y = x + 12 = 22 + 12
y = 34
