Question

a增加p%得b,b减少q%得a,那么p与q的关系是

Answer 1

a增加p%得b

a(1+p%)=b

b/a=1+p%

b减少q%得a

b(1-q%)=a

b/a=1/(1-q%)

所以1+p%=1/(1-q%)

(1+p/100)(1-q/100)=1

1-q/100+p/100-pq/10000=1

pq/10000-p/100+q/100=0

pq-100p+100q=0