Bob the builder is making 480 kg of concrete mix. Concrete is made by mixing cement, sand and gravel in the ratio 1 : 3 : 4 how much sand does he need ?
+179 Um... You should add up 1, 3 and 4 (that equals 8) and divide 480 (kg) by the sum, which is 60, then look for context clues and realize that in the ratio, there is 3 sand so you evaluate the product of 60 and 3, which is 180 kg.
Also, good job, Guest! 
