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3 years ago

15

A builder makes a certain type of concrete by mixing together 1 part portland cement (made from lime and clay), 3 parts sand, an

d 5 parts crushed stone. If 765 ft^3 of concrete are needed, how many cubic feet of each ingredient does he need?

1 answer:

Mariana [72]3 years ago

3 0

Answer:

85 ft^3 portland cement
255 f^3 sand
425 ft^3 crushed stone

Step-by-step explanation:

The total number of parts is 1+3+5 = 9. The relevant fractions of the mix are ...

1/9 = portland cement

3/9 = 1/3 = sand

5/9 = crushed stone

Since the total is 765 ft^3, the ingredients required are ...

(1/9)(765 ft^3) = 85 ft^3 portland cement

(1/3)(765 ft^3) = 255 f^3 sand

(5/9)(765 ft^3) = 425 ft^3 crushed stone

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