Maths * Henry is mixing concrete. To make concrete he needs to mix cement, sand and gravel in the ratio 4 : 3 : 1 by weight. Henry needs to make 120kg of concrete. He has 55kg of cement, 45kg of sand and 15kg of gravel. Which ingredient is Henry short of?

Question

Mathematics

Madelynn Forbes

5 September, 05:03

Maths * Henry is mixing concrete. To make concrete he needs to mix cement, sand and gravel in the ratio 4 : 3 : 1 by weight. Henry needs to make 120kg of concrete. He has 55kg of cement, 45kg of sand and 15kg of gravel. Which ingredient is Henry short of?

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Answers (1)

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Bosley · Answer 1

His 55 kg of cement is 5 kg short of the 60 kg he needs.

Step-by-step explanation:

Let r be a ratio useful in determining how much of each ingredient Henry needs:

4/8 of the mix is cement, 3/8 is sand and 1/8 is gravel.

4/8 of the total 120 kg must then be 60 kg made up of cement;

3/8 must then be 45 kg made up of sand; and

1/8 must then be 15 kg made up of gravel

His 55 kg of cement is 5 kg short of the 60 kg he needs.