SOLUTION: Given an arithmetic sequence in which a1=3 a5=19 and an=163 what is n?

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Question 934289: Given an arithmetic sequence in which a1=3 a5=19 and an=163 what is n?
Answer by mananth(16946) About Me  (Show Source):
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a1=3 a5=19 and an=163 what is n?
an = a1+(n-1)d
a1=3
a5= a1+4d
19=3+4d
4d=16
d=4
an=163
163=3+(n-1)4
163=3+4n-4
164=4n
n=41