Question

Seutas tali dibagi menjadi 6 potong.Panjang tali terpendek 3cm dan yang terpanjang 96cm.Panjang tali mula2 adalah.. cm.

#Barisan Geometri⊕

Answer 1

U6 = ar^5

a = 3

ar^5 = 96
3r^5 = 96
r^5 = 96/3
r^5 = 32
r = 2

Sn = a(r^n - 1)/(r - 1)
= 3(2^6 - 1)/(2 - 1)
= 3(64 - 1)/1
= 3(63)
= 189 cm

Answer 2

U1 = 3
U6 = 96

ar^5 / a = 96/3
r^5 = 32
r^5 = 2^5
r = 2

Sn = a (r^n - 1) / r - 1
S6 = 3 (2^6 - 1) / 2 - 1
S6 = 3 (64 - 1) / 1
S6 = 3 x 63
S6 = 189