An A. P. consists of 89 terms of which 3rd term is 14 and the last term is 272. Find the 39th term.
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Answer:
122
Step-by-step explanation:
3rd term=14
n=3, A3=14
An=a+(n-1)d
A3=a+(3-1)d
14=a+2d--eq1
89th term=272
n=89, A89=272
An=a+(n-1)d
A89=a+(89-1)d
272=a+88d--eq2
Add eq1 and eq2, we get
86d=258
d=258/86
d=3
Substitute d=3 in eq1
a+2d=14
a+2(3)=14
a+6=14
a=14-6
a=8
39th term
a=8, d=3, n=39
An=a+(n-1)d
A39=8+(39-1)3
A39=8+(38)3
A39=8+114
A39=122
Therefore, the 39th term is 122.
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