In the A.P. 7,14,21,... How many terms are to be consideredfor getting sum 5740. (ans:40)
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Answered by
0
5740=n/2(14+(n-1)7)
solving this will give u 2 and but negative should be excluded
solving this will give u 2 and but negative should be excluded
dattubhai:
then
put b= -1
a=1
who says
c=1680
ok
a=n^2 and b=n
Atharva Shetty the value of c=1640 and not 1680 Bro! !
by mistake i wrote that
i know that
Answered by
1
ACCORDING TO THE FORMULA
Sn= n/2 (2a+(n-1)*d)
5740 = n/2 (2*7+(n-1)*7)
5740 =n/2 (14+7n-7)
5740*2=n (7+7n)
Or,7n^2+7n=11480
Or, n^2+n-1640
Using Sridhara Acharya formula(done in my notebook sorry can't show the process to you.) Therefore n= 4 but n is not equal to -10/2
because n being the no. of terms cannot be negative, not possible.
So,4 terms are required for getting the sum of AP 5740.
Sn= n/2 (2a+(n-1)*d)
5740 = n/2 (2*7+(n-1)*7)
5740 =n/2 (14+7n-7)
5740*2=n (7+7n)
Or,7n^2+7n=11480
Or, n^2+n-1640
Using Sridhara Acharya formula(done in my notebook sorry can't show the process to you.) Therefore n= 4 but n is not equal to -10/2
because n being the no. of terms cannot be negative, not possible.
So,4 terms are required for getting the sum of AP 5740.
sorry the ans is 40
How!!
you do the sum and find s40 ok and see
Yeah my mistake!!!
I usually never do this sorry Bro! !
Ask for more questions if you stuck . perhaps I can help you wit
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