Twenty times nine thousand equals 180000
Answer: Both trains would meet at 1 pm
Step-by-step explanation:
Let t represent the time at which both trains will pass each other.
The distance between the cities is 360 miles. This means that by the time both trains meet, the total distance covered would be 360 miles.
Distance = speed × time
The freight train is travelling at 50 mph. Distance covered by the freight train in t hours is 50t.
The passenger train is travelling at 70 mph. Distance covered by the passenger train in t hours is 70t.
Since the total distance covered is 360 miles, it means that
50t + 70t = 360
120t = 360
t = 360/120
t = 3 hours
Both trains would meet at 1 pm
A.) The temperature rises 10 degrees over 3 hours.
(To explain my reasoning is because at 0 hours the temperature was 30 then at 3 hours the temperature moved up to 40 and at 6 the temperature moved to 50 which means every 3 hours its moving up 10 degrees)
Solving a system of equations, we will see that there are 6000 kg of coal on the pile.
<h3>
How many kilograms of coal are in the pile of coal?</h3>
Let's say that there are N kilograms of coal, and it is planned to burn it totally in D days, these are our variables.
We know that:
- If the factory burns 1500 kilograms per day, it will finish burning the coal one day ahead of planned.
- If it burns 1000 kilograms per day, it will take an additional day than planned.
Then we can write the system of equations:
(1500)*(D - 1) = N
(1000)*(D + 1) = N
Because N is already isolated in both sides, we can write this as:
(1500)*(D - 1) = N = (1000)*(D + 1)
Then we can solve for D:
(1500)*(D - 1) = (1000)*(D + 1)
1500*D - 1500 = 1000*D + 1000
500*D = 2500
D = 2500/500 = 5
Now that we know the value of D, we can find N by replacing it in one of the two equations:
(1500)*(D - 1) = N
(1500)*(5 - 1) = N
(1500)*4= N = 6000
This means that there are 6000 kilograms of coal on the pile.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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