Answer:

Explanation:
There are only two mutually exclusive possibilities for each complex electronic system: being <em>defective</em> or being <em>not defective</em>:
- Number of complex electronic systems: 7
- Nmber of defective systems: 2
- Number of not defective systems: 5
<em>Probability </em>that no defective systems are found in the sample is the equal to the probability of selecting them consecutively without replacement and finding each one is not defective:
- Porbability the first is not defective × probability the second is not defective
- 5/7 × 4/6 = 20/42 = 10/21
The greatest common factor is 2b
Answer:
10/39
Step-by-step explanation:
The chances of picking a black sock on first try are 8/13, and the chances of picking out a yellow sock without replacing the black sock are 5/12. If you multiply 8/13 and 5/12, you get 40/156, and if you simplify, you will get 10/39 as your answer.
Answer:

Step-by-step explanation:
Given


Required
Determine the percentage change
Percentage change is calculated as;






<em>Hence, the percentage change is approximately 8.8%</em>
Answer:
the third option
Step-by-step explanation:
what does that mean ?
to "rationalize" it is to transform it into a rational number (that is a number that can be described as a/b, and is not an endless sequence of digits after the decimal point without a repeating pattern).
a square root of a not square number is irrational (not rational).
so, what this question is asking us to get rid of the square root part in the denominator (the bottom part).
for this we need to multiply to and bottom with the same expression (to keep the whole value of the quotient the same) that, when multiplied at the bottom, eliminates the square root.
what can I multiply a square root with to eliminate the square root ? the square root again - we are squaring the square root.
so, what works for 9 - sqrt(14) as factor ?
we cannot just square this as
(9- sqrt(14))² = 81 -2sqrt(14) + 14
we still have the square root included.
but remember the little trick :
(a+b)(a-b) = a² - b²
without any mixed elements.
so, we need to multiply (9-sqrt(14)) by (9+sqrt(14)) to get
81-14 = 67 which is a rational number.
therefore, the third answer option is correct.