# If you mixed 80 tons of sand, 12 tons of rock, and 4.0 tons of cement to make concrete, what would the percent by weight of sand be?

##### 1 Answer

Aug 29, 2016

#### Answer:

The percent by mass would be 83 %.

#### Explanation:

The mass percent of a component in a mixture is given by the formula

#color(blue)(|bar(ul(color(white)(a/a) "Mass Percent" = "Mass of component"/"Mass of mixture" × 100 % color(white)(a/a)|)))" "#

In your problem,

∴