Knewton DS

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Knewton DS

by rahulvsd » Mon Aug 22, 2011 7:58 pm
At a certain circus, every child was given either two or three balloons. How many children received three balloons?

1. At the circus, 40 percent of the children received two balloons.
2. A total of 390 balloons were given out to children at the circus.



OA:c
Source: — Data Sufficiency |

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by sl750 » Mon Aug 22, 2011 10:20 pm
Statement 1 tells us the respective percentages of balloon received by each group, but we don't know how many are in each group. Insufficient

Statement 2 gives us the total number of children. Insufficient

Combining the two, we have 60%(390) who receive 3 balloons. Sufficient

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by GMATGuruNY » Tue Aug 23, 2011 2:31 am
rahulvsd wrote:At a certain circus, every child was given either two or three balloons. How many children received three balloons?

1. At the circus, 40 percent of the children received two balloons.
2. A total of 390 balloons were given out to children at the circus.



OA:c
Statement 1: 40 percent of the children received two balloons each.
Out of every 10 children:
4 received 2 balloons each, for a total of 4*2 = 8 balloons.
6 received 3 balloons each, for a total of 6*3 = 18 balloons.
Thus, the fraction of the balloons given to the children who received 3 balloons each = 18/(8+18) = 9/13.
No way to determine the number of children who received 3 balloons each.
Insufficient.

Statement 2: A total of 390 balloons were given.
No way to determine the number of children who received 3 balloons each.
Insufficient.

Statements 1 and 2 combined:
The number of balloons given to the children who received 3 balloons each = (9/13)*390 = 270.
Thus, the number of children who received 3 balloons each = 270/3 = 90.
Sufficient.

The correct answer is C.
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