word problem mixture

Question

a bag of powdered driveway sealant call for addition of 5 quarts of water for every 30 pounds of sealant. How much water should be added if only 20 pounds of sealant will be used

Answer 1

This one is a simple ratio

 

if you need 5 quarts for 30 pounds how many quarts for 20 pounds

 

5/30 = x/20

 

Now solve for x

 

x = 10/3 or 3 1/3

 

Another way to look at it would be to say 20 pounds is 2/3 of 30 pounds  (20/30) so you need 2/3 of the 5 quarts of water, 2/3 of 5 = 10/3 or 3 1/3

 

All the best

 

Lori