math question do fast pls pls
Attachments:
Answers
Answered by
1
since sum is given by n/2(a+l)
400=(n/2)(5+45)
n=16
Now sum is also given by (n/2)(2a+(n-1)d)
400=8(10+15d)
from here u will get d
400=(n/2)(5+45)
n=16
Now sum is also given by (n/2)(2a+(n-1)d)
400=8(10+15d)
from here u will get d
Answered by
2
HERE IS THE ANSWER.
___________________
First term,a=5
last term,an=45
sum of all terms,Sn=400
Sn=n/2(a+an)
400=n/2(5+45)
400=n/2(50)
400=25n
n=400/25
n=16.
now,putting value of n in an
an=a+(n-1)d
45=5+(16-1)d
45=5+15d
45=5(1+3d)
45/5=1+3d
9=1+3d
10=3d
d=10/3
therefore,common difference is 10/3.
_____________________
PLEASE MARK AS BRAINLIEST.
___________________
First term,a=5
last term,an=45
sum of all terms,Sn=400
Sn=n/2(a+an)
400=n/2(5+45)
400=n/2(50)
400=25n
n=400/25
n=16.
now,putting value of n in an
an=a+(n-1)d
45=5+(16-1)d
45=5+15d
45=5(1+3d)
45/5=1+3d
9=1+3d
10=3d
d=10/3
therefore,common difference is 10/3.
_____________________
PLEASE MARK AS BRAINLIEST.
Similar questions