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j_shreyans
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1In a stack of boards at a lumber yard, the 20th board counting from the top of the stack is immediately below the 16th board counting from the bottom of the stack. How many boards are in the stack ?
A. 38
B. 36
C. 35
D. 34
E. 32
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19 = 16
20 = 15
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1
In the rendering above:
The red values represent the number of boards when counting from the TOP.
The blue values represent the number of boards when counting from the BOTTOM.
The two middle rows with big numbers satisfy the constraint that RED BOARD 20 is directly below BLUE BOARD 16.
Total number of boards = (red boards 1-18) + (2 middle rows with big numbers) + (blue boards 1-14) = 18+2+14 = 34.
The correct answer is D.
