17/4 + 17/4 + 17/4 = 51/4 cups
51/4 = 12 3/4 cups
Since the beacons rotate together, the angular speed is constant.
From the time you see the first beacon, you have to wait for the lighthouse to make 120°, i.e. 1/3 of a whole turn.
So, if T is the time it takes for the lighthouse to make a whole turn, the interval between the first and the second beacon is T/3.
The interval between the second and third beacon is the amount of time it takes to the lighthouse to make the remaining 2/3 of a turn, so that you'll see the first beacon again. So, this time is 2T/3
So, the ratio is
So, the time between the second and third beacon is twice as much the time between the first two.
The tail of the train starts one mile from the mouth of the tunnel and it must travel that distance plus the length of the tunnel in 3 minutes.
Let t = tunnel length
t + 1 = distance the tail must travel in 3 minutes.
3 minutes = 1/20 hr
(t+1) miles / 60 m/hr = 1/20 hr
t + 1 = 60/20
t+1 = 3
Subtract 1 from each side:
t = 2
The tunnel is 2 miles long.
<h3>
Answer: m = 25</h3>
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Work Shown:
Triangle ABC is congruent to triangle DEF. The order of the lettering is important because it tells us how the angles pair up. We see that angle B and angle E are the second letters of ABC and DEF respectively. Because the triangles are congruent, this leads to angle B = angle E.
Angle B is shown to be 20 degrees, so,
angle E = angle B
2(m-15) = 20
m-15 = 20/2
m-15 = 10
m = 10+15
m = 25
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A slightly alternative way to solve:
2(m-15) = 20
2m-30 = 20
2m = 20+30
2m = 50
m = 50/2
m = 25
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Checking the answer:
2(m-15) = 20
2(25-15) = 20
2(10) = 20
20 = 20
We get the same thing on both sides, so we end up with a true equation. This means the first equation is true when m = 25. The solution has been confirmed.
