Find the sum of the series: 2 + 5 + 8 + 11 + ... + 59
neel1419:
d= 5-2=3, Now last term = first term + (n-1)d=59 by solving it you will get n=20, Now sum of the series = n. (1st term +last term)÷2 by solving it you will get your answer
Answers
Answered by
3
a= 2 , d= 3 & tn= 59 = l
tn= a+(n-1)d
59=2+(n-1)3
59=2+3n-3
59=3n-1
60=3n
n= 60/3=20
sum of the series = n/2(a+l) =20/2(2+59)=10×61=610
tn= a+(n-1)d
59=2+(n-1)3
59=2+3n-3
59=3n-1
60=3n
n= 60/3=20
sum of the series = n/2(a+l) =20/2(2+59)=10×61=610
Similar questions