Answer:
15
Step-by-step explanation:
1 dime = 10
1 quarter=25
x=number of coins - dimes
y= number of coins - quarters
x (10)+y(25)=10.25
x+y=50
x= 50-y
x(10)+y(25)=1025
(50-y)(10)+25y =1025
500-10y+25y=1025
500+15y=1025
15y= 1025 - 500
15y=525
y=525/15
y=35
x= 50-35=15
Answer: See explanation
Step-by-step explanation:
a. Marisa drives 112 miles in 1 hour and 45 minutes, which means her speed is 64 miles per hour.
Speed = Distance / Time
= 112 / 1 45/60
= 112 / 1 3/4
= 112 × 4/7
= 64 miles per hour.
TRUE
b . If 6 pens cost $7.74, then 7 pens cost $9.03.
Cost of one pen = $7.74/6 = $1.29
Cost of 7 pens = $1.29 × 7 = $9.03
TRUE
c. If Raymond drives at a speed of 57 miles per hour, then it takes him 4 hours and 10 minutes to drive 256.5 miles.
Speed = Distance / Time
Speed = 256.5 / 57 = 4.5 = 4 hours 30 minutes
FALSE
d. If 17 identical cans of soup cost $38.59, then 3 of the cans must cost $6.81.
Cost of one can = $38.59 / 17 = $2.27
Cost of 3 cans = $2.27 × 3 = $6.81
TRUE
e. Mr. Mayes buys two dozen eggs for $8.40, which means that he pays 70 cents per egg.
A dozen = 12
2 dozens = 12 × 2 = 24
Cost of one egg = $8.40 / 24 = 0.35 = 35 cents
FALSE
If you multiply length times width to get area, it's the same with division. You do area divided by length or width. The equation would be 225 divided by 13 3/4. 225/13 3/4= 16.36 inches. 16.36 > 16 inches, so the answer would be no. (The mirrors length and width are 13 3/4 inches by 16 9/25)
Answers:
- (a) Independent
- (b) Dependent
- (c) Dependent
- (d) Independent
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Explanation:
If events A and B are independent, then the two following equations must both be true
- P(A | B) = P(A)
- P(B | A) = P(B)
This is because the conditional probability P(A|B) means "P(A) when B has happened". If B were to happen, then P(A) must be the same as before. In other words, event B does not affect A, and vice versa.
For part (a), we have P(B) = 1/4 and P(B|A) = 1/4 showing that P(B|A) = P(B) is true, and therefore we can say the events are independent. We don't need the info that P(A) = 1/8.
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Unlike part (a), part (b) has the answer "dependent" because P(A) = 1/8 and P(A | B) = 1/3 differ in value. Event A starts off at probability 1/8, but then event B occurring means P(A) gets increased to 1/3. The prior knowledge about B changes the chances of A. The P(B) = 1/5 is unneeded.
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If A and B were independent, then,
P(A and B) = P(A)*P(B)
However,
P(A)*P(B) = (1/4)*(1/5) = 1/20
which is not the same as P(A and B) = 1/6. Therefore the two events are dependent.
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Refer back to part (a)
P(A) = 1/4 and P(A|B) = 1/4 are identical in value, so P(A|B) = P(A) which leads to the events being independent. Whether we know event B happened or not, it does not affect the outcome of event A. P(B) = 1/9 is unneeded.
Answer:
2.75, and - 2.75
Step-by-step explanation:
Both have an absolute value of 2.75 which is how far away they are from 0.
Hope this helped!
