三分之一加十五分之一加三十五分之一加六十三分之一等于多少

1/3+1/15+1/35+1/63
=5/15+1/15+1/35+1/63
=2/5+1/35+1/63
=14/35+1/35+1/63
=15/35+1/63
=27/63+1/63
=28/63
=4/9