Answer:
c + 3d = 14.75
2c + 5d = 26
A box of candy is $4.25 and a drink is $3.50
Step-by-step explanation:
Let c represent the cost of a box of candy and let d represent the cost of a drink
c + 3d = 14.75
2c + 5d = 26
Solve by elimination by multiplying the top equation by -2
-2c - 6d = -29.5
2c + 5d = 26
Add them together
-d = -3.5
d = 3.5
Plug in 3.5 as d into one of the equations to solve for c
c + 3d = 14.75
c + 3(3.5) = 14.75
c + 10.5 = 14.75
c = 4.25
So, a box of candy is $4.25 and a drink is $3.50
Line that never touch each other
Answer:
0.2611 = 26.11% probability that exactly 2 calculators are defective.
Step-by-step explanation:
For each calculator, there are only two possible outcomes. Either it is defective, or it is not. The probability of a calculator being defective is independent of any other calculator, which means that the binomial probability distribution is used 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.
5% of calculators coming out of the production lines have a defect.
This means that 
Fifty calculators are randomly selected from the production line and tested for defects.
This means that 
What is the probability that exactly 2 calculators are defective?
This is P(X = 2). So
0.2611 = 26.11% probability that exactly 2 calculators are defective.
Answer:
- 6 2/3 qt 80%
- 13 1/3 qt 20%
Step-by-step explanation:
It is often convenient to solve a mixture problem by letting a variable represent the quantity of the higher-concentration contributor to the mix.
__
We can let x represent the number of quarts of 80% solution needed. Then (20-x) is the number of quarts of 20% solution needed. The amount of salt in the final mix is ...
0.80x +0.20(20-x) = 0.40(20)
0.60x = 0.20(20) . . . . . . . . subtract 0.20(20) and simplify
x = 20/3 = 6 2/3 . . . . . . . . . divide by 0.60; quarts of 80% solution
(20 -x) = 13 1/3 . . . . . . . . . . amount of 20% solution needed
The teacher should mix 6 2/3 quarts of 80% solution with 13 1/3 quarts of 20% solution.
the length of segment AB is 13
