find the fifth term oa AP when the first term is 50000 and the common difference is 4500
Answers
Values of n = 16 and
Values of n = 16 and d = 8/3
Step-by-step explanation:
Let a , d , l are first term , common difference and last term of an A.P , respectively.
given ,
a = 5, l = 45
We know that,
\boxed {last \:term \:(l)=a+(n-1)d }lastterm(l)=a+(n−1)d
Substitute values of a and l , we get,
=> 45 = 5+(n-1)d
=> 45-5 = (n-1)d
=> (n-1)d=40 ----(1)
\begin{gathered}\boxed {Sum\: of\: n\: terms \:(S_{n})\\= \frac{n}{2}(a+l)}\end{gathered}
S_{n}=400Sn=400 \* given *\
\implies \frac{n}{2}(5+45)=400⟹2n(5+45)=400
\implies n\times \frac{50}{2}=400⟹n×250=400
\implies n = 400 \times \frac{2}{50}⟹n=400×502
\implies n = 8 \times 2⟹n=8×2
\implies n = 16⟹n=16
Now ,
Substitute n=16 in equation (1), we get
(16-1)d = 40
=> 15d =40
=> d = 40/15
=> d = 8/3
Therefore,
Values of n = 16 and
d = 8/3
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Step-by-step explanation:
and -<br /><br />10 cm respectively. Find the magnification and decide the type <br /><br />of lens used and nature of the image.