plz..help me with ques.35
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Hey
Here is your answer,
In attachment.
Hope it helps you!
Here is your answer,
In attachment.
Hope it helps you!
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Sn=200 a=20 d=-1 n= number of rows
Sn=n/2(2a +(n-1)d)
400=n(40-n+1)
400=n(41-n)
n^2 -41n +400
n^2-16n-25n+400
n(n-16)-25(n-16)
(n-16) (n-25)
n=16 Ans
n=25 (neglecting because it will be answer in -ve which is not possible)
Tn=a+(n-1)d=20-15=5 Ans
Sn=n/2(2a +(n-1)d)
400=n(40-n+1)
400=n(41-n)
n^2 -41n +400
n^2-16n-25n+400
n(n-16)-25(n-16)
(n-16) (n-25)
n=16 Ans
n=25 (neglecting because it will be answer in -ve which is not possible)
Tn=a+(n-1)d=20-15=5 Ans
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