Speed is the ratio of distance and time.
So, average speed= Total distance/ total time.
Let's assume t is the time taken for going from New Orleans to Boston and it's taking 1 hour less to return back. So, time taken for return back is t-1.
Given the speed from New Orleans to Boston is 40 mph. So,
Distance = Speed * time
So, d =40 t
Hence t= d/40
Similarly Distance for returning back:
d =80 (t-1)
d/80 = t-1 (Dividing 80 to each sides)
Now the total distance= d+ d = 2d
And total time : t + t -1= d/40 + d/80
So, the average speed = ![\frac{2d}{\frac{d}{40}+\frac{d}{80}}](https://tex.z-dn.net/?f=%20%5Cfrac%7B2d%7D%7B%5Cfrac%7Bd%7D%7B40%7D%2B%5Cfrac%7Bd%7D%7B80%7D%7D%20%20%20%20)
=
(cancel out d )
Common denominator of 40 and 80 is 80. So, multiply each terms by 80.
=
=![\frac{160}{2+1}](https://tex.z-dn.net/?f=%20%5Cfrac%7B160%7D%7B2%2B1%7D%20%20)
=![\frac{160}{3}](https://tex.z-dn.net/?f=%20%5Cfrac%7B160%7D%7B3%7D%20%20)
=53.33 mph
So, the average speed is 53.33 mph.
Answer:
y + 6 = -15/13(x-7)
Step-by-step explanation:
Substitute m= -15/13 and the point (7,-6) into the point slope form.
y --6 = -15/13 (x - 7)
y + 6 = -15/13(x-7)
Answer:
5 4/9
Step-by-step explanation:
7/9 of 7
" of " in math means multiply
7/9 * 7 = 49/9 = 5 4/9 <==
Answer:
29. A 30. C 31. C
Step-by-step explanation:
2/5+1/4+1/6=49/60
60-49=11 >>> 11/60
176/2pi = 28.0
3.89 - hundredths place but not so sure because if you round you get 3.90 so either D or C