Question

rice are $2.00 per lbs. and sugar are $4.00 per lbs. I bougth a total of 10 pounds of both for $27.00 How many pounds of each did i get?

Answer 1

r+s=10

2r+4s=27
Multiply the first equation by -2 to cancel the r's.
-2r-2s=-20
2r+4s=27
2s=7
s=3.5
Put s back into either original equation to solve for r (the first one would be easier).