1. Determine the number of board feet required for joists on a one-story house 30′ × 40′, in which 2 × 8 joists will be placed 16″ OC.

Question

A. 2,052

B. 1,224

C. 1,632

D. 1,536

I believe the answer is B. 1,224
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2. A 4 × 12 built-up girder is 30″. How many board feet does this girder contain? (Round your answer to the nearest whole number.)

A. 107

B. 312

C. 128

D. 96

I think the answer is C.128.
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3. Calculate the number of hours needed to frame a one-story house 36′ long, in which 2 × 6 × 16 joists will be placed 16″ OC. (Round your answer to the nearest whole number.)

A. 4
B. 5
C. 7
D. 6

I think it's B. 5 hours.