Answer:
There is a 24.3% probability that one of the calculators will be defective.
Step-by-step explanation:
For each calculator, there are only two possible outcomes. Either it is defective, or it is not. So we use the binomial probability distribution to solve this problem.
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.
The probability of a defective calculator is 10 percent.
This means that 
If 3 calculators are selected at random, what is the probability that one of the calculators will be defective
This is P(X = 1) when n = 3. So


There is a 24.3% probability that one of the calculators will be defective.
Step-by-step explanation:
First you convert 10 to 30/3 and then convert 8 2/3 to 26/3 and then you subtract 30-26 which will be 4/3.
Answer:
if it says 12x = 7
the u will divide the 12 on both sides and x will equal to 7/12,,
if it simply says 12 = 7 then put false cause that's not true!!
Answer:
D. 2 1/6
Step-by-step explanation:
To visualize the problem easier, start by converting all the fractions to improper fractions, this will allow you to just add the denominators and simplify the question:
1/6, 5/6, 1 3/6 —> 1/6, 5/6, 9/6
Now that the sequence is rewritten, you can simply add 4 to the numerator, which equals 13/6.
Rewrite this again by finding how many times 6 goes into 13, and use the remainder as the numerator of the new fraction, which will end up as 2 1/6.
Answer:
Step-by-step explanation:
Last year
Ratio of the number of middle school students to number of high school students = 1 : 8
Total ratio = 9
Middle school = 1
High school = 8
Total students in the band = x
Middle school = 1/9x
High school = 8/9x
Total = 1/9x + 8/9x
This year
Ratio of the number of middle school students to number of high school students = 2 : 7
Total ratio = 9
Middle school = 2
High school = 7
Total students = x
Middle school = 2/9x
High school = 7/9x
Total = 2/9x + 7/9x
If there are 18 middle school students in the band this year
2/9x = 18
x = 18÷2/9
= 18 × 9/2
= 81
x = 81
Last year:
1/9x + 8/9x
= 1/9 * 81 + 8/9 * 81
= 9 + 72
= 81
This year
2/9x + 7/9x
2/9*81 + 7/9*81
= 18 + 63
=81
Change in middle school =this year - last year
= 18 - 9
= 9 (increase)
Change in high school = this year - last year
= 63 - 72
= -9 (decrease)