SOLVE

LATER

Vanya and Students again !

Problem

Editorial

Analytics

Vanya has to now choose some Students from her class to go to the International Mathematical Olympiad. She knows for each student of her class, *3* pieces of information about them, i.e. their 'Name', 'Age' and 'Aptitude'.

Vanya, to make work easier for her, and more difficult for you, defines the **Winning Quotient** of the Students choosen for the Olympiad from her class to be the Summation of their Aptitude Levels. In short, assume Vanya chooses Students *x*, *y* and *z*. She considers the **Winning Quotient** to be Aptitude Level(x) + Aptitude Level(y) +Aptitude Level(z) in case of such a selection.

Now, considering that Vanya randomly chooses any arbitrary subset of Students from her class to visit the Olympiad, where the size of this subset has to be at least *1*, and the probability of each subset being choosen is equal, Vanya wishes to know the Expected Value of the **Winning Quotient** of the choosen Students.

She finds this task rather challenging, and wants you to help her out. Can you do it ?

Table : Students

Field | Type |
---|---|

Name | text |

ID | text |

Aptitude | int |

Round down your answer to **2** decimal places, and then select it to output.

**Sample Students Table** :

Name | ID | Aptitude |
---|---|---|

Micro | 12abcd | 1 |

Vanya | 13abcd | 2 |

Rhezo | 14abcd | 3 |

**Output**

Answer |
---|

3.43 |

**Input Constraints** :

The input table shall consist of no more than 10 rows. The Aptitude level of each student shall lie in the range from *1* to \(10\) inclusive. The Name and ID of each Student shall consist of at least 1 and no more than 10 characters.

Time Limit:
5 sec(s)
for each input file.

Memory Limit:
256 MB

Source Limit:
1024 KB

Marking Scheme:
Marks are awarded when all the testcases pass.

Allowed Languages:
MySQL,
PostgreSQL,
MSSQL,
Oracle_Db

Initializing Code Editor...

{"17faf31": "/pagelets/show-submission/sql/vanya-and-students-again/", "3fc9f4d": "/pagelets/suggested-problems/sql/vanya-and-students-again/", "c3879be": "/pagelets/recommended-problems/sql/vanya-and-students-again/", "8a3b9e9": "/pagelets/problem-author-tester/sql/vanya-and-students-again/", "cec1b2f": "/pagelets/problems-hint/sql/vanya-and-students-again/"}

realtime.hackerearth.com

80

fbdee0e1f593bf9bac63374e1af60d708d2bdb18

58a29e5cae2309f04b28

/realtime/pusher/auth/