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❓The half-hour newscast includes 12 minutes of national news, 5 minutes of international news, 5 minutes of sports, and 2 minutes of weather forecasts. The rest is advertisements. How many minutes of advertising are in the newscast?
💡First, I need to determine the total duration of the newscast, which is 30 minutes.Next, I'll add up the durations of the different segments:- National news: 12 minutes- International news: 5 minutes- Sports: 5 minutes- Weather forecasts: 2 minutesAdding these together: 12 + 5 + 5 + 2 = 24 minutes.Finally, I'll subtract the total time spent on these segments from the overall duration to find the time allocated to advertisements:30 minutes (total duration) - 24 minutes (news, sports, and weather) = 6 minutes.Therefore, there are 6 minutes of advertising in the newscast.
❓A traffic light cycles as follows: green for 45 seconds, yellow for 5 seconds, then red for 50 seconds. Felix chooses a random five-second interval to observe the light. What is the probability that the color changes while he is observing?
💡First, I need to determine the total duration of one complete cycle of the traffic light. The light is green for 45 seconds, yellow for 5 seconds, and red for 50 seconds. Adding these together gives a total cycle time of 100 seconds.Next, I'll identify the points during the cycle when a color change occurs:- The light changes from green to yellow at the 45-second mark.- It changes from yellow to red at the 50-second mark.- Finally, it changes from red to green at the 100-second mark, which is also the start of the next cycle.Felix observes the light for a random five-second interval. For him to witness a color change, his observation period must overlap with one of the transition points. Specifically, he must start observing within five seconds before each changeover:- From green to yellow: 40 to 45 seconds.- From yellow to red: 45 to 50 seconds.- From red to green: 95 to 100 seconds.Each of these intervals is 5 seconds long, and there are three such intervals in total. Therefore, the total favorable time for observing a color change is 15 seconds.Finally, to find the probability that Felix observes a color change, I'll divide the total favorable time by the total cycle duration:[frac{15}{100} = frac{3}{20}]
❓Simplify frac{120}{180}.
💡To simplify the fraction (frac{120}{180}), I first need to determine the greatest common factor (GCF) of the numerator and the denominator. I'll start by factoring both numbers into their prime factors.For the numerator, 120:[120 div 2 = 60 60 div 2 = 30 30 div 2 = 15 15 div 3 = 5 5 div 5 = 1]So, the prime factorization of 120 is (2^3 cdot 3 cdot 5).For the denominator, 180:[180 div 2 = 90 90 div 2 = 45 45 div 3 = 15 15 div 3 = 5 5 div 5 = 1]So, the prime factorization of 180 is (2^2 cdot 3^2 cdot 5).Next, I'll identify the common prime factors and take the lowest powers of these to determine the GCF:- The common prime factors are 2, 3, and 5.- The lowest power of 2 is (2^2).- The lowest power of 3 is (3^1).- The lowest power of 5 is (5^1).Therefore, the GCF is:[2^2 cdot 3 cdot 5 = 4 cdot 3 cdot 5 = 60]Now, I'll simplify the fraction by dividing both the numerator and the denominator by the GCF:[frac{120}{180} = frac{120 div 60}{180 div 60} = frac{2}{3}]Thus, the simplified form of (frac{120}{180}) is (boxed{frac{2}{3}}).
❓Amanda now decides to draw six circles with radii 2, 3, 4, 5, 6, 7. For each circle, she plots three points (C, D, A) on a graph, where C is the circumference, D is the diameter, and A is the area. Determine which of the following properties is true regarding the plotted points.- C and D show a direct linear relationship.- C and A show a direct linear relationship.- D and A show a direct linear relationship.A) C and D show a direct linear relationship.B) C and A show a direct linear relationship.C) D and A show a direct linear relationship.D) None of the relationships are linear.
💡Okay, so Amanda is drawing six circles with radii 2, 3, 4, 5, 6, and 7. For each circle, she's plotting three points: C for circumference, D for diameter, and A for area. I need to figure out which of the given properties is true regarding these plotted points. The options are about whether C and D, C and A, or D and A have a direct linear relationship. If none of these are linear, then the answer would be D.First, I should recall the formulas for circumference, diameter, and area of a circle. The circumference C is given by ( C = 2pi r ), the diameter D is ( D = 2r ), and the area A is ( A = pi r^2 ). So, all these quantities depend on the radius r.Let me list out the values for each circle:For r = 2:- C = 2π*2 = 4π- D = 2*2 = 4- A = π*(2)^2 = 4πFor r = 3:- C = 2π*3 = 6π- D = 2*3 = 6- A = π*(3)^2 = 9πFor r = 4:- C = 2π*4 = 8π- D = 2*4 = 8- A = π*(4)^2 = 16πFor r = 5:- C = 2π*5 = 10π- D = 2*5 = 10- A = π*(5)^2 = 25πFor r = 6:- C = 2π*6 = 12π- D = 2*6 = 12- A = π*(6)^2 = 36πFor r = 7:- C = 2π*7 = 14π- D = 2*7 = 14- A = π*(7)^2 = 49πNow, let's analyze the relationships:1. **C and D**: From the formulas, C = 2πr and D = 2r. If I express C in terms of D, since D = 2r, then r = D/2. Substituting into C, we get C = 2π*(D/2) = πD. So, C is directly proportional to D with a constant of proportionality π. This is a linear relationship because as D increases, C increases by a constant factor.2. **C and A**: C is linear in r, while A is quadratic in r. Let's see if there's a linear relationship. If I try to express A in terms of C, from C = 2πr, we get r = C/(2π). Substituting into A, A = π*(C/(2π))^2 = π*(C^2)/(4π^2) = C^2/(4π). This is a quadratic relationship, not linear. So, C and A do not have a direct linear relationship.3. **D and A**: D is linear in r, and A is quadratic in r. Let's express A in terms of D. Since D = 2r, r = D/2. Substituting into A, A = π*(D/2)^2 = π*(D^2)/4. Again, this is a quadratic relationship, not linear. So, D and A do not have a direct linear relationship.Therefore, the only direct linear relationship is between C and D.**Final Answer**boxed{A}
❓A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered. If the required fencing is 76 feet, what is the area of the field?
💡First, I need to determine the dimensions of the rectangular field. I know that one side is 20 feet and that the total fencing required for the other three sides is 76 feet.I'll denote the length of the uncovered side as ( L = 20 ) feet and the width of the other two sides as ( W ).The total fencing covers two widths and one length, so I can set up the equation:[2W + L = 76]Substituting the known value of ( L ):[2W + 20 = 76]Next, I'll solve for ( W ):[2W = 76 - 20][2W = 56][W = frac{56}{2}][W = 28 text{ feet}]Now that I have both the length and the width, I can calculate the area of the field:[text{Area} = L times W][text{Area} = 20 text{ feet} times 28 text{ feet}][text{Area} = 560 text{ square feet}]
❓Sally picks 30 seashells on Monday. On Tuesday, she picks some seashells. If she can sell each seashell for 1.20, she can make 54 if she sells all of her seashells. What is the ratio of the number of seashells picked on Tuesday to the number picked on Monday?
💡First, I need to determine the total number of seashells Sally has by dividing the total earnings by the price per seashell.Next, I'll subtract the number of seashells picked on Monday from the total to find out how many she picked on Tuesday.Finally, I'll calculate the ratio of the seashells picked on Tuesday to those picked on Monday and simplify it.