Memory type - DS

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Memory type - DS

by karthikpandian19 » Wed Dec 14, 2011 12:41 am
Each M-type memory unit will increase the base memory capacity of a certain computer by 3 megabytes. What is the base memory capacity, in megabytes of the computer?
(1) 2 M-type memory units will increase the computers base memory capacity by 300 percent
(2) The memory capacity of the computer after 2 M-type memory units are added to the base memory capacity is 1.6 times the memory capacity of the computer after 1 M-type memory unit is added to the base memory capacity.
Source: — Data Sufficiency |

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by rijul007 » Wed Dec 14, 2011 1:25 am
karthikpandian19 wrote:Each M-type memory unit will increase the base memory capacity of a certain computer by 3 megabytes. What is the base memory capacity, in megabytes of the computer?
(1) 2 M-type memory units will increase the computers base memory capacity by 300 percent
(2) The memory capacity of the computer after 2 M-type memory units are added to the base memory capacity is 1.6 times the memory capacity of the computer after 1 M-type memory unit is added to the base memory capacity.
(1) 2 M-type memory units will increase the computers base memory capacity by 300 percent

Base memory = x MB
New memory = 4x = x + 2*3
3x = 2*3
x = 2MB

Sufficient



(2) The memory capacity of the computer after 2 M-type memory units are added to the base memory capacity is 1.6 times the memory capacity of the computer after 1 M-type memory unit is added to the base memory capacity.

Base mem = x MB
x+2*3 = 1.6*(x+3)
x+6 = 1.6x + 4.8
0.6x = 1.2
x = 2MB

Sufficient

Option D

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by Anurag@Gurome » Wed Dec 14, 2011 2:17 am
karthikpandian19 wrote:Each M-type memory unit will increase the base memory capacity of a certain computer by 3 megabytes. What is the base memory capacity, in megabytes of the computer?
(1) 2 M-type memory units will increase the computers base memory capacity by 300 percent
(2) The memory capacity of the computer after 2 M-type memory units are added to the base memory capacity is 1.6 times the memory capacity of the computer after 1 M-type memory unit is added to the base memory capacity.
Let the base memory capacity be x MB.

(1) x + 6 = 100% of x + 300% of x
x + 6 = 4x
x = 2; SUFFICIENT.

(2) x + 6 = 1.6(x + 3), which can be solved for x; SUFFICIENT.

The correct answer is D.
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