PS - printing throughput

If it takes 6 identical printing presses 4 hours to print 5000 newspapers, how long would it take to print 3 of these presses to print 3000 newspapers?

A. 3 hours, 20 minutes
B. 4 hours, 20 minutes
C. 4 hours, 48 minutes
D. 5 hours, 48 minutes
E. 6 hours, 50 minutes

source: www.800score.com

PS - Length of a segment

In the diagram above, BD = 8, AB = 6 and ED=5? What is the length of AE? (Note: figure not drawn to scale.)

A. 3
B. 4
C. 5
D. 7
E. 10

source: www.800score.com

PS - Microchip price

The price of a microchip declines 67 percent every 6 months. At this rate, approximately how many years will it take for the price of an $81 microchip to reach $1 ?

A. 1.5
B. 2
C. 3
D. 13
E. 13.5

source: www.800score.com

PS - perimeter of an equilateral triangle

The figure shows a square inscribed within an equilateral triangle. If the side X of the square measures 12 inches, then what is the perimeter of the equilateral triangle (in inches)?

A. 36
B. 36 x sqrt(3)
C. 36 x sqrt(3) + 24
D. 24 x sqrt(3) + 36
E. 72

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note: sqrt(x) stands for the square root of x

source: http://www.800score.com/gmat/