Question

For an a.p. a=20, tn:200, n:10 find sn ​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Step-by-step explanation:

If a=20 , An = 200 and n = 10

An = a + (n-1) d

200 = 20 + (10 -1)d

200= 20 + 9d

200-20=9d

180=9d

d=20

Sn=n\2{2a+(n-1)d}

=10\2{2×20+(10-1)20}

=5{40+180}

=220×5

=1100