Question

从1至60这60个自然数中取出8个数,使它们的倒数之和是1,这8个数是哪些?

Answer 1

3,5,6,10,12,15,30,60

1/3+1/5+1/6+1/10+1/12+1/15+1/30+1/60

=（20+12+10+6+5+4+2+1）/60

=60/60

=1