Answer:
179.159
Step-by-step explanation:
Given the sequence :
50, 60, 72,..
The sequence given is a geometric sequence :
For a geometric sequence ;
ar^(n - 1)
a = first term
r = a2 / a1 = 60 / 50 = 1.2
The 8th term ; n =8
a8 = ar^(n - 1)
a8 = 50*1.2^(8 - 1)
a8 = 50*1.2^7
a8 = 50*3.5831808
a8 = 179.15904
a8 = 179.159 (nearest thousandth )
Answer: The running speed of Elena is 5 miles/hour and this can be determined by using the formula of speed.
Step-by-step explanation:
A circular running track 1/4 is a mile long.
Elena runs on this track, completing each lap in 1/20 of an hour.
Speed formula is used to determine the speed of Elena. The formula of speed is given by:
----- (1)
where S is the speed, D is the distance and T is the time taken by Elena to run a circle.
Now, put the value of distance D and time T in the equation (1).
Speed = 5 miles/hour
Therefore, the running speed of Elena is 5 miles/hour.
For more information, refer to the link given below:
brainly.com/question/22610586
Not enough information to give a dependable answer