dengan jalannya........ ....

u3 = 32
u7 = 2
r^(7-3) = 2/32
r⁴ = 1/16 = 1/2⁴
r = ½

u3 = ar² = 32
a x ½² = 32
a x ¼ = 32
a = 32/¼ = 32 x 4 = 128 = 2^7

S10 = 128 x (1 - ½^10)/(1-½)
= 128 x 2 x (1.024-1)/1.024
= 256/1.024 x 1.023
= 1.023/4
= 255 ¾

jawaban : C