First find the common denominator 5/8=25/40 2/5=16/40 3/4=30/40 Next you can cross multiply 25/40=x/10 pounds 16/40=x/10 pounds 30/40=x/10 pounds First 25(10)/40= 6.25 pounds 16(10)/40= 4pounds 30(10)/40= 7.5 pounds These are the amounts that were left in the bag
10-6.25=3.75 10-4=6 10-7.5=2.5
3.75+6+2.5= 12.25
All together they put 12.25 pounds of soil in the flower bed