There is 7 friends (A1, A2, A3....A7).If A1 have to have shake with all without repeat. How many handshakes possible? Pick one: A) 6 B) 21 C) 28 D) 7 E) 5
a1 with (a2, a3,a4,a5,a6,a7)   6 handshakes   6NSWER:6
<result>A</result>
There is 7 friends (A1, A2, A3....A7).If A1 have to have shake with all without repeat. How many handshakes possible?