Waterloo 2022 Fall C - Squaring the Triangle
View as PDF2022 Fall Waterloo Local Contest, Problem C
Wesley creates a graph  that contains 
 vertices. For each pair of vertices 
, there is a probability
of 
 that an edge exists between 
 and 
. The probabilities are independent of each other.
Let  denote the number of triangles in 
. A triangle is a set of 
 vertices that are connected by 
 edges.
Please help Wesley find the expected value of .
Input Specification
Line  contains integer 
 
, the number of cases.
 lines follow. The 
 line contains integers 
 
, separated by spaces.
Output Specification
Output  lines, one line for each case.
Suppose the answer to the  case is 
, in lowest terms. Output 
. That is, output
a number 
 such that 
 and 
.
Sample Input
2
3 1 2
4 1 2
Sample Output
125000001
875000007
Note
The original problem did not have a sample.
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