A train goes twice as fast downhill as it can go uphill, and 2/3 feet as fast uphill as it can go on level ground. If it goes 120 miles per hour downhill, how long will it take to travel 45 miles per flat

0.5hrs

Step-by-step explanation:

Let the speed downhill be ,

Speed uphill is . We are told than speed uphill is the speed on flat ground. Therefore the speed on level ground will be .

From this info, we can obtain the actual speed, on level ground as:

speed, distance and time have the relation so to obtain time to cover 45miles:

Hence it takes 0.5hrs to cover 45miles on flat ground.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

no

step-by-step explanation: