Problema Solution
A mixture of concrete uses 420 pounds of stone,100 pounds of cement, and 120 pounds of sand.what is the total weight of dry mixture? what reduced fraction of the mix is sand? a different job needs two thirds of the mix.how much sand,stone,and cement is needed?
Answer provided by our tutors
total weight of mixture = 420+100+120 = 640 pounds
percentage of sand in the mix = (120/640)*100=18.75%
For new job 2/3rd of mixture is required i.e 640*2/3= 426.666 pounds
In order to have mixture we shall mix
Sand =2/3*420=280 pounds
Stone=2/3*100=66.66 pounds
Cement=2/3*120=80 pounds