Question

(1)利名商店运来橘子.苹果和梨共260千克.其中橘子和苹果的质量比是5:6,梨的质量是橘子的五分之二,梨有多少千克?

Answer 1

1.260/(1+6/5+2/5)

=260/(13/5)

=100

100*(2/5)=40

2. (1-10%)(1-10%)

=90%*90%

=81%