It can be said that most of the required information's are already given in the question.
Let us assume the speed of the passenger train = x
Speed of the freight train = y
x = y + 40
The second equation will be
6 * x = 10 * y
6x = 10y
Dividing both sides by 2, we get
3x = 5y
x = 5y/3
Putting the value of "x" in the first equation, we get
x = y + 40
5y/3 = y + 40
5y = 3y + 120
5y - 3y = 120
2y = 120
y = 60 mph
Putting the value of y in the first equation, we get
x = y + 40
= 60 + 40
= 100 mph
From the above deduction, we can conclude that the passenger train is traveling at 100 mph and the freight train is traveling at 60 mph.
If a teacher had 48 red pens and the ratio of red to blue pens she owns is 6:1, she will have a total of 56 pens
Let the number of red pens be R and the number of blue pens be B.
R = 48
R / B = 6 / 1
48 / B = 6 / 1
B = 48 / 6
B = 8
Total number of pens = Number of red pens + Number of blue pens
Total number of pens = R + B
Total number of pens = 48 + 8
Total number of pens = 56 pens
Therefore, she has a total of 56 pens
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Answer:
13.4cm
Explanation:
According to Rayleigh’s criterion the angular resolution to distinguish two objects is given by:

θ = 50.0*10^-7 rad
λ: wavelength of the light = 550nm
b = diameter of the objective
By doing b the subject of the formula and replacing the values of the angle and wavelength you obtain:

hence, the smallest diameter objective lens is 13.4cm
Answer:
V = 6 m/s
Explanation:
Given that,
Initial speed of an object is 20 m/s
Final speed of an object is 10 m/s
Time, t = 5 s
We need to find the average speed of the object during these 5 seconds. Let it is equal to V. Here, time is same. The average speed is given by :

So, the average speed of the object is 6 m/s.