The average rate, in miles per hour, of the rail portion of the trip is; D: 75
<h3>How to calculate the average speed?</h3>
Since exactly 1/3 of the distance travelled was by rail, then we can say that;
(1/3) * (90) = 30 miles
We are told that part of the trip took 1/5 of the travel time. Thus;
Time it takes to travel that distance is:
(1/5) * (2) = 2/5 of an hour
Average rate is;
30/(2/5) = 150/2 = 75 mph
Read more about Average speed at; brainly.com/question/4931057
#SPJ1
It’s D
11x= 6x + 5x
10^2 + 6x + 5x + 3
2x(5x+3)+5x+3
Step-by-step explanation:
=( 5 + 1 )2 - ( 12 + 32 ) + 3
=6 * 2 - 44 + 3
=12 - 44 + 3
= -29
<span>for part (a) find the sum of the first n terms of the arithmetic series. for part (b) find n for the given sum Sn.
45. 3+8+13+18+23+...
a. n=20
b. Sn=366
46. 50+42+34+26+18+...
a. n=40
b. Sn=182
47. -10+(-5)+0+5+10+...
a. n=19
b. Sn=375
48. 34+31+28+25+22+...
a. n=32
b. Sn=-12
49. 2+9+16+23+30+...
a. n=68
b. Sn=1661
50. 2+16+30+44+58+...
a. n=24
b. Sn=2178
</span>
