13. how many cubic yards of concrete are needed to pour 6 footings that measure 2' 6"
by 1' 6" by 12" inches deep? (note: 2' 6" = 2.5', 1' 6" = 1.5', and 12" = 15)

0.8325 cubic yards.

Step-by-step explanation:

The dimensions of each footings is given by 2.5 feet by 1.5 feet by 1 foot.

{Because 2'6" ≡ 2.5' ≡ 2.5 feet, 1'6" ≡ 1.5' ≡ 1.5 feet and 12" ≡ 1' ≡ 1 foot}

So, volume of each footing = 2.5 × 1.5 × 1 = 3.75 cubic feet.

Therefore, the total volume of 6 footings is (3.75 × 6) = 22.5 cubic feet.

Now, we know that 1 cubic foot is equivalent to 0.037 cubic yards.

So, 22.5 cubic feet is equal to 0.8325 cubic yards.  

Therefore, 0.8325 cubic yards of concrete are needed to pour 6 footings. (Answer)

21/58.

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