Bunuel
A spaceship in orbit rotates around the planet Pluto. How many full rotations can the spaceship complete in 20 hours?
(1) The radius of the rotation is 21,000 miles.
(2) The spaceship travels at 35 miles per second.
Statement 1)
Radius of rotation = 21,000 miles
Distance traveled to complete one rotation = 2 x pie x r = 2 x 3.14 x 21,000
As no info with regard to speed of rotation is given ..
Insufficient Rule out Choice A) & D)
Statement 2)
Speed of Spaceship = 35 miles/ sec = (35x60x60)/hour
As no info with regard to distance is given ..
Insufficient Rule out Choice B)
Statement 1) & 2) combined
Distance traveled in 20hours = 35x60x60x20
=> No of rotations complete = (35x60x60x20)/(2x3.14x21000) = 19.10 [in the test there is no requirement to actually solve the calculation]
The question specifically asks for no. of full rotations
Hence ans = 19 .. Sufficient
Answer Choice C) is correct.
Good luck
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