A person travels from New York to Washington at the rate of 45 km per hour and
comes backs to the New York at the rate of 55 km per hour. What is his average
speed for the whole journey?

The average speed for the whole journey is 49.5 miles per hour.

Explanation:

Step 1 :

Here, both the ways, he covers the same distance.  Then, the formula to find average speed is

=  2xy / (x+y)

Step 2 :

x > Rate at which he travels from New York to Washington  

x  =  45

y > Rate at which he travels from New York to Washington  

y  =  55

Step 3 :

So, the average speed is

=  (2 ⋅ 45 ⋅ 55) / (45 + 55)

=  4950 / 100

=  49.5

colorectal cancer may also develop from areas of abnormal cells in the lining of the colon or rectum. this area of abnormal cells is called dysplasia and is more commonly seen in people with certain inflammatory diseases of the bowel such as crohn's disease or ulcerative colitis.

unbalanced force

explanation: