Question

In an Ap given a=5, d=3,an=50, find n and sn

Answer 1

an=50
a+(n-1)d=50
5+(n-1)3=50
3n-3=50-5
3n=50+3-5
3n=48
n=48/3
n=16

sn=n/2 (2a+n

Answer 2

Answer:

Step-by-step explanation:

a=5, d=3, an=50, n=?, Sn=?

= a+(n-1)×d=50

=5+(n-1)×3=50

=5+3n-3=50

=3n=48

=n = 48/3

= n = 16

Now, let's find Sn=?

Sn= n/2

Sn=16/2[2a+(16-1)d]

=8[2×5+15×3]

=440

Hence, n=16 and S16 or Sn=440

Hope you guys understood and clear!!