Answer:
180 kg
Step-by-step explanation:
The ratio is
cement : sand : gravel
1 : 3 : 4
If he used 1 kg cement, 3 kg sand, and 4 kg gravel, he'd get 8 kg of concrete.
He wants to make 480 kg of concrete.
480/8 = 60
He needs 60 times more concrete than the numbers in the ratio.
60 * 3 kg = 180 kg
Answer: 180 kg
