When testing for current in a cable with nine ​color-coded wires the author used a meter to test three wires at a time. How many different tests are required for every possible pairing of three ​wires

Answer 1

Would think that this is 9C3 as order should not matter

this is 9!/(6!)(3!) which is 9 x 8 x 7/ 3 x 2

which is 84