x- 18=(x-6)5/8
x- 18=5/8x- 15/4
3/8x= 14 and 1/4.
x=57/4×8/3
x=38
There are 38 bags of flour and 38 bags of rice in the canteen.
2、 18÷( 1-5/7)
= 18×7/2
=63
63÷ 18=3.5 liters
The volume of each tank of water is 3.5 liters.
3, 60+60×25%=75 yuan
60-60×25%=45 yuan
60×2-(75+45)=0
These two clothes didn't make a profit or lose money.
4、=2009×(2000+ 10)/20 10×(3000- 1)+2009
=40 18000+20090/6030000-20 10+2009
=4038090/6029998
=20 19045/30 14999
≈0.67
5、=6/ 12+2/ 12+ 1/ 12+ 1/20+ 1/30+ 1/42
=9/ 12+ 1/20+ 1/30+ 1/42
=45/60+3/60+2/60+ 1/42
=5/6+ 1/42
=35/42+ 1/42
=36/42
=6/7