Question

把一堆皮球分别装进4个盒子,5分之一放进甲盒,3分之一放进乙盒

Answer 1

10/[1-1/5-1/3-75%*(1/5+1/3)]

=10/[1-8/15-8/15*3/4]

=10/[1-8/15-6/15]

=10/[1/15]

=10*15

=150个