Answer:
20 mph
Step-by-step explanation:
Let speed of Train a = Va mph
Let speed of Train b = Vb mph
Va = Vb + 30
Let time taken for Train a = Ta
Let time taken for Train b = Tb
time taken = distance travelled/speed
Ta = 350/Va = 350/(Vb+30)
Tb = 140/Vb
But they both travel in the same amount of time.
So, Ta = Tb

Cross multiply

Divide both sides by 210

Their least common multiple is 90 .
90 = 5 x 18
90 = 2 x 45
Answer:
B. 
Step-by-step explanation:
We know that the constant is $75. You only pay this once.
Whereas $0.55 you pay per mile. Which means that you will multiply 0.55 by how many miles you drive.
This means that the equation will look like:

Hope this helps! :)
I think 4 is the answer.I hope this help you
Answer:
A or $89.98
Step-by-step explanation:
49.99 x 2 = 99.98. 99.98 - 10.00 = 89.98