Question

Concrete is made by mixing screenings cement and sand in the ratio 3:1:15. How much sand would be needed

to make 125 tonnes of concrete?

Answer 1

98.7 tonnes of sand.

Explanation:

First find the total :

3 + 1 + 15 = 19

if 19 = 125 tonnes,

what about 15 = ?

(cross multiply)

`(15)/(19) * 125`

= 1875 ÷ 19

= 98.68

(rounded off to 1 decimal place)

= 98.7 tonnes of sand.