You can set up a proportion to solve for the percentage of the coins that are pennies. Of course, there are alternate methods as well, but this is one method. First, you define the percentage of the coins that are pennies to be equal to a variable, such as x. Next, you write 240/600 = x/100, due to how "x" is the amount out of 100 (since per cent is for every cent (out of 100)), and 240 would correspond to x while 600 would correspond to 100. This proportion may also be written as 100/x = 600/240, or 240/x = 600/100. In order to solve for x, you use cross-products, or you multiply each denominator by the numerator of the other fraction. You will be left with a numerical value that's equal to a number times x, and then you divide both sides of the equation by the coefficient of x in order to isolate x. As a result, you will have the percentage of the coins that are pennies to be your answer. Remember to write the units for every numerator and denominator in your proportion.
Answer:
$2.72
Step-by-step explanation:
The increase from last week is the fraction ...
(new price)/(old price) -1 = (1.82/1.65) -1 = 17/165
so the amount of increase Sally will pay this week is ...
17/165×$26.40 = $2.72
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<em>Comment on the working</em>
We could work this several ways. Perhaps most straightforward would be to determine how many gallons Sally bought last week, and multiply that by the change in price. Or, the number of gallons could be multiplied by the new price per gallon and the difference from the old purchase amount found.
If you look at the numbers, you see that we have effectively done it the first way. The change in price is $0.17 per gallon, and the number of gallons Sally bought is $26.40/$1.65.
Answer:
x = 4 or x = 12
Step-by-step explanation:
Given:
y = -10x² + 160x - 430
When y = $50
50 = -10x² + 160x - 430
50 + 430 = -10x² + 160x
480 = -10x² + 160x
-10x² + 160x - 480 = 0
Divide through by -10
x² - 16x + 48 = 0
Solve the quadratic equation using factorization method
+48 = -12 × -4
-16 = -12 -4
Therefore,
-12 and -4 are both factors
x² - 16x + 48 = 0
(x - 4 )(x - 12 ) = 0
x - 4 = 0
x = 4
OR
x - 12 = 0
x = 12
I think very well that it is A or B. With my experience, but you might want to keep doing research.
Answer:
Step-by-step explanation:
The persons who have diseases = 19%
The persons who do not have diseases = 81%
Probability for the test showing positive = Prob of actual disease and shows positive + Prob of no disease but test shows wrong
= 
Prob that the person actually has the disease given that the test administered to an individual is positive= 
30) A B C total
2x 7x x 10x
P(A) = 0.2, P(B) = 0.7, P(C) = 0.1
Let D be the event that the product is defective
P(D/A) = 0.032, P(D/B) = 0.034 and P(D/C) = 0.056
Required probability =P(C/D)
= 
by using Bayes theorem for conditional probability
= 
32) 7 digit phone numbers with repitition including 0 will be
= 
Numbers which have atleast one 7 = total number - numbers which do not have a single 7
= 
the probability that a 7-digit phone number contains at least one 7
=
