First, to make things easier, let's turn 5/4 into a decimal given a second is equal to 1000 milliseconds.
5/4 = 1,25
1,25 * 1000 = 1250 milliseconds = 1.25 seconds
So, we've found that 45 yards can be covered in 1.25 seconds. Now we'll use the rule of 3:
45 - 1.25
80 - x
Now we solve:
(80 * 1.25) / 45 = x
100 / 45 = x
2,22... = x
So, according to our answer, 80 yards can be covered in 2,22 seconds, which in fractions would be:

Hope it helped,
BioTeacher101
Answer:4
Step-by-step explanation:
2+2 = 4
Adding 2 in 2 gives us 4.
Let
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are

where
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if
, and we know that this happens after two hours, i.e. at 

Solving this equation for v we have

So, train A is travelling at 105 km/h. This implies that train B travels at

Answer: 15
Step-by-step explanation:
1/3x - 2 = 3
1/3x = 5
x = 15