square shaped planks

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square shaped planks

by rahulvsd » Tue Nov 08, 2011 7:39 pm
A 40-foot long platform connects two adjacent buildings, and the platform is made up of a one-plank-wide strip of square-shaped planks. How many planks comprise the platform?

(1) Each plank has a diagonal of 5√2 feet.

(2) Each plank has a width of 5 feet.

[spoiler]OA:D[/spoiler]
Source: — Data Sufficiency |

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by user123321 » Tue Nov 08, 2011 8:07 pm
rahulvsd wrote:A 40-foot long platform connects two adjacent buildings, and the platform is made up of a one-plank-wide strip of square-shaped planks. How many planks comprise the platform?

(1) Each plank has a diagonal of 5√2 feet.

(2) Each plank has a width of 5 feet.

[spoiler]OA:D[/spoiler]
1) plank's length = 5 feet
=> number of planks required = 40/5 = 8. hence sufficient
2) plank's length = 5 feet
=> same as above. hence sufficient.

user123321
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