crackgmat007 wrote: Since order does not matter, divide by 2!).
can you explain the above pls.
Also, answer seems to be B, not sure if OA is wrong...can someone clarify
AMO PQR is the same as MAO RPQ. Without the 2! you would have both of these in your total list of arrangements and you really need only 1. That is what is meant by order is not important. Regarding the OA,
AM OPQR
Since AM can't move, we have 4 choices of one person to join them. Take O. Then you have one group comprising AMO
You are left with PQR. In how many ways can these three people form a group of 3? Only 1 way. They have no choice even if they hate each other. That means the total ways is 4 x1 =4
Consider another approach. . So we want
AM + 1 of OPQR. imagine you have formed AMO the 4C1 way as above. So you have 1 team already and you want the other team. Fix R. That leaves 2 persons P and Q. You want these 2 to join R . But that can be done in 2C2 ways =1. In order words if AM MUST be together here are all the possibilities.
AMO PQR
AMP OQR
AMQ POR
AMR POQ
The OA says 30%. To have 30% we must have 3/10. I don't see how you get a 3 in the numerator.How can you only have 3 in the numberator when you have 4 possibilities?
