Question

Given a=5,d=3 An=50 find n and Sn

Answer 1

HERE'S YOUR ANSWER

a = 5 d = 3 an = 50

an = a + (n - 1)d

50 = 5 + (n - 1)3

45 = 3n - 3

48 = 3n

n = 16

Sn = n/2(a + an)

Sn = 16/2(5+50)

Sn = 8(55)

Sn = 440