please help me in this question
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8/13 is answer..
I hope it's help you..
I hope it's help you..
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Mohit0:
how do you got the value of m
im sorry but please tell me
ok i understood it thanks for your efforts
I can't understand how m=5 came?can you tell ?please
Can you tell how the value for m came?
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let the two AP's be a1,a2,a3,,,,,,,,,,,,,and b1,b2,b3,,,,,,,,,,,
given ratio of their sum of n terms,
sna/snb=(3n+5)/(5n+7)
by multiplying n to both numerator and denominator we get,
sna/snb=(3n^2+5n)/(5n^2+7)
We know that,
anth term=snth term-s(n-1)th term
therefore ratio of n th term,
an/bn=[3n^2+5n-{(3(n-1)^2-5(n-1)}]/[5n^2+7n-{5(n-1)^2+7(n-1)}]
we get above step by replacing n by (n-1).
an/bn=[3n^2+5n-{3n^2+3-6n+5n-5}]/[5n^2+7n-{5n^2+5n-10n+7n-7}]
by solving we get,
an/bn=(6n+2)/(10n+2)=(3n+1)/5n+1)
this is the ratio n th terms of those AP's
now by substituting n=5, we get
(a5th term) /(b5th term) =(3×5+1)/(5×5+1)
=16/26=8/13
Hence ratio of their 5 th term is equals to 8/13.
given ratio of their sum of n terms,
sna/snb=(3n+5)/(5n+7)
by multiplying n to both numerator and denominator we get,
sna/snb=(3n^2+5n)/(5n^2+7)
We know that,
anth term=snth term-s(n-1)th term
therefore ratio of n th term,
an/bn=[3n^2+5n-{(3(n-1)^2-5(n-1)}]/[5n^2+7n-{5(n-1)^2+7(n-1)}]
we get above step by replacing n by (n-1).
an/bn=[3n^2+5n-{3n^2+3-6n+5n-5}]/[5n^2+7n-{5n^2+5n-10n+7n-7}]
by solving we get,
an/bn=(6n+2)/(10n+2)=(3n+1)/5n+1)
this is the ratio n th terms of those AP's
now by substituting n=5, we get
(a5th term) /(b5th term) =(3×5+1)/(5×5+1)
=16/26=8/13
Hence ratio of their 5 th term is equals to 8/13.
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