Question

The ratio of sand to cement in amixture of concrete is 2 to 7. Howmany bags of sand are needed to mixwith 42 bags of cement?A 8B 12C 18D 49

Answer 1

The ratio of sand to cement is 2:7. Now, consider the following diagram:

now, by cross-multiplication, we get:

`(x)(7)=\text{ (2)(42)}`

solving for x, we get:

`x\text{ = }((2)(42))/(7)`

this is equivalent to:

`x\text{ = 12}`

so that, we can conclude that the correct answer is B:

12