Marcus drives to school at an average speed of 24 miles per hour and returns home along the same route at an average
speed of 40 miles per hour. if his total travel time is 4 hours, what is the total number of miles in the round trip to and from
school?

ANSWER:

The total number of miles in the round trip to and from school for Marcus is 120 miles  

SOLUTION:

Given, Marcus drives to school at an average speed of 24 miles per hour and returns home along the same route at an average speed of 40 miles per hour.  His total travel time is 4 hours,  

We have to find what is the total number of miles in the round trip to and from school?

Let, the distance between his school to home be d.

And, time taken to go to school be t, then time taken reach home becomes 4 – t.  

We know that, distance = speed x time.

While going to school, d = 24 x t → (1).

While going to home, d = 40 x (4 – t) → (2)

Now equate both (1) and (2)

24t = 40(4 – t) → 24t = 160 – 40t  

→ 24t + 40t = 160 → 64t = 160

Now, substitute t in (1) → d = 24 x 2.5 → d = 60 miles.

So, number of miles in the round trip = 60 + 60 = 120 miles.

Hence, Marcus travels 120 miles in total.

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this