barisan geometri U4= 16 dan U6=64, suku ke 10 barisan tersebut adalah

U6/U4 = 64/16
ar^5/ar³ = 4
r² = 4
r² = 2²
r = 2

U4 = 16
ar³ = 16
a = 16/r³ = 16/2³ = 16/8 = 2

S10 = ar^9 = 2(2^10) = 2(1024) = 2048