# how many different tests are required for every possible pairing of two wires?when testing for current in a cable with five color coded wires, the author used a meter to test two wires at a time.

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### 1 Answer

The number of different wires present = 5

The number of wires tested at a time = 2

There for number of possible ways given by `^5C_2`

Number of possible pairings `= ^5C_2`

`= (5!)/(2!3!)`

` = 10`

**There are 10 possible pairings.**