Mathematics for IGCSE & O level - Ratio And Proportion (Section 1 - No. 47)
A certain type of concrete mixture requires cement, sand, and gravel in a ratio of 1:2:3. If you have 10 kg of cement, how much gravel do you need?
5 kg
10 kg
20 kg
30 kg
คำอธิบาย
Cement:Sand:Gravel=1:2:3. Thus if cement is 10kg, 1*10=10, so gravel = 3*10 = 30