Answer:
-21.5
Step-by-step explanation:
-12-6=-18 minus 3.5=-21.5
Mom drove for 11 hours.
Dad drove for 3 hours.
<u>Step-by-step explanation</u>:
- Total distance = 895 miles
- Mom drove a speed of 65 mph
- Dad drove a speed of 60 mph
Let 'x' be the number of hours drove by mom.
Let 'y' be the number of hours drove by dad.
x + y = 14 ---------------(1)
65x + 60y = 895 ---------(2)
Multiply eq(1) by 60 and subtract eq(2) from (1),
60x + 60y = 840
-(<u>65x + 60y = 895</u>)
<u> -5x = -55 </u>
x = 55/5
x = 11
∴ Mom drove for 11 hours.
Substitute x=11 in eq(1)
11+y = 14
y = 3
∴ Dad drove for 3 hours.
Answer:
1.15%
Step-by-step explanation:
To get the probability of m independent events you multiply the individual probability of each event. In this case we have m independent events, each one with the same probability, therefore:


This is a particlar scenario of binomial distribution problem. So the binomial distribution questions are about the number of success of m independent events, where every individual event has the same p probability. In the question we have 20 events and each event has a probability of 80%. The binomial distribution formula is:

n is the number of events
k is the number of success
p is the probability of each individual event
is the binomial coefficient
the binomial coefficient allows to find the subsets of k elements in a set of n elements. In this case there is only one subset possible since the only way to get 20 of 20 correct questions is to getting right all questions (for getting 19 of 20 questions there are many ways, for example getting the first question wrong and all the other questions right, or getting second questions wrong and all the other questions right, etc).

therefore, for this questions we have:

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4.
a. $100
b. $360
The formula to find the answers to these kinds of problems is p * r * t. The rate is always a decimal, so if the rate is 8%, you multiply by 0.08. If the rate is 12%, you multiply by 0.12, and so on.
5.
a. 12.8
b. 31 1/6
I got these answers by doing the distributive property. Replace each variable with the number it represents, multiply each by two and add them up to get these answers. For the fraction one, you can set up each fraction by finding the LCD before multiplying by 2, or you can find a fraction calculator online and add the numbers up.
6.
a. x = 20
b. x = 3
c. x = 13
d. x = 0
e. x = 4
f. x = 7
g. x = -3
I solved this problem by doing the distributive property and doing these kinds of problems step by step. It’s long to explain, but hopefully your teacher has good notes for you to look back on over these types of questions. If there is only a negative sign in front of the distributive property equation, then you basically distribute -1 to each number. In these long equations, combine like terms. You must do these kinds of questions right, because it’s easy to mess up and get wrong answers if you don’t do the right steps in order.