Question

the first term of an arithmetic sequence is 10 , twenteth term 60. calculate the sum of first 20 terms​

Answer 1

Answer:

given: a=10, l=60, n=20

wkt,

Sn= n/2 (a+l)

S20 = 20/2 (10+60)

S20 = 10(70)

S20=700

hope it helps ü........^_^