a, 1 + 1/5 + 1/25 + 1/125 + 1/625
= 625/625 + 125/625 + 25/625 + 5/625 + 1/625
= \(\frac{625+125+25+5+1}{625}\)
= 781/625
b,1/3 + 1/6 + 1/12 + 1/24 + 1/48 + 1/96
= 32/96 + 16/96 + 8/96 + 4/96 + 2/96 + 1/96
= \(\frac{32+16+8+4+2+1}{96}\)
= 63/96 = 21/32