in an Ap , if a=5 , an=20 and Sn=441 find n
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a=15
an=20
d=?
Sn=441
n=?
Sn=(a+l)
=>n(15+20)=441×2
=>n(35)=441×2
=>n=441×2/35
=>n=25.2
Now,
an=a+(n-1) d
=>20=15(25.2-1)d
=>20=15×24.2×d
=>d=343
The nth term is 25.2 and d=343
an=20
d=?
Sn=441
n=?
Sn=(a+l)
=>n(15+20)=441×2
=>n(35)=441×2
=>n=441×2/35
=>n=25.2
Now,
an=a+(n-1) d
=>20=15(25.2-1)d
=>20=15×24.2×d
=>d=343
The nth term is 25.2 and d=343
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