37.5%乘7分之5加7分之1乘8分之3加8分之3除以7
=37.5%*5/7+1/7*3/8+3/8*1/7
=3/8*5/7+1/7*3/8+3/8*1/7
=3/8*(5/7+1/7+1/7)
=3/8*1=3/8