jumlah 3½+4½+5½+...+98½ adalah..? a.4508 b.4700 c.4896 d.5096 jawabannya c kan?? minta caranya dong

a = 3,5
b = 1
Un = 98,5
Un = a+(n-1)b
98,5 = 3,5+(n-1)1
98,5 = 3,5+n-1
98,5 = 2,5+n
n = 98,5-2,5 = 96

Sn = n/2(a+Un)
S96 = 96/2(3,5+98,5) = 48(102) = 4.896