Answer:
C. The value of the series is equal to the value of the 1st or 24th numbers in the series.
Step-by-step explanation:
The given series is [tex]S_{24}=\sum_{k=1}^{24}-6+0.5k[/tex].
To find the first term of this series, we substitute k=1 to obtain:
[tex]a_1=-6+0.5(1)=-6+0.5=-5.5[/tex]
To find the 24th term of the series, we put k=24 to get:
[tex]a_{24}=-6+0.5(24)=-6+12=6[/tex]
The value of the series is the sum of all the terms in the series.
We can find the value of the series using the formula:
[tex]s_{n}=\frac{n}{2}(a_1+l)[/tex].
In this case, the last term is [tex]a_{24}=l[/tex].
[tex]\implies s_{24}=\frac{24}{2}(-5.5+6)[/tex].
[tex]\implies s_{24}=12(0.5)[/tex].
[tex]\implies s_{24}=6[/tex].
Now let us analyse the options:
A. The value of the series is greater than the value of the 24th number in the series.
False: because 6 is not greater than 6.
B. The value of the series is between the values of the 1st and 24th numbers in the series.
False: because 6 is not between -5.5 and 6
C. The value of the series is equal to the value of the 1st or 24th numbers in the series.
True: In logics, an "or" statement (disjunction) is true if one of the alternatives is true. In this case the sum of the series is equal to the 24th number of the series because 6=6 is true
D. The value of the series is less than the value of the 1st number in the series.
False: because 6 is not less than -5.5