Question

a=8, an=62, sn=120. Find n and d.​

Answer 1

HEY MATE I THINK THE VALUE OF Sn is 210

Give- a=8 , an=62 , Sn=210

we know that,

sn = n/2(a+an)

210 = n/2(8+62)

420 = n(79)

420/70 = n

n = 6

we also know that,

an = a+(n-1)d

62 = 8+(6-1)d

62-8 = 5d

54 = 5d

d = 54/5 (or) 10.8

THEREFORE, THE VALUE OF 'n' AND 'd' ARE

"6" AND "54/5"

HOPE THIS MAY HELP YOU