Dear All,
I have few questions on probability, that's
1) sunitha wants to make a necklace. she has 8 beads how many different choices does she have?
2)from city A to B there are 3 different roads, from B to C there are 5, from C to D there are 2.Laxman has to go from city A to D attending some work in city B and C on the way and has to come back in the reverse order.In how many ways can he complete his journey if he has to take a different while coming back than he did while going?
Hello, vijayayarra!
Both problems are poorly worded.
I must make some guesses . . .
1) Sunitha wants to make a necklace. She has 8 beads.
How any different choices does she have?
I will assume that there are 8 distinguishable beads,
. . perhaps of 8 different colors.
I will also assume that her necklace will have all 8 beads,
. . and that the question is: "How many different necklaces can be made?"
Placing 8 items in a circle, there are: . ways.
But half of them are mirror-images of the other half.
Therefore, there are: . possible necklaces.
2) From city A to B there are 3 different roads,
from B to C there are 5, and from C to D there are 2.
Laxman has to go from city A to D attending some work
in cities B and C on the way and has to come back in the reverse order.
In how many ways can he complete his journey if he has to
take a different route while coming back than he did while going?
Going from A to D, there are: . choices.
Now what is meant by "a different route"?
If it means that no road can be used more than once,
then on the return trip, there are:
. . 1 choice for D-to-C,
. . 4 choices for C-to-B,
. . 2 choices for B-to-A.
Hence, there are: . choices for the return trip.
If "a different route" means even slightly different, then the trip from D to A
. . must not be exactly the same as the route from A to D.
Then there are: . choices for the return trip.
Hello,
1) sunitha wants to make a necklace. she has 8 beads how many different choices does she have?
Ans. 1200
2)from city A to B there are 3 different roads, from B to C there are 5, from C to D there are 2.Laxman has to go from city A to D attending some work in city B and C on the way and has to come back in the reverse order.In how many ways can he complete his journey if he has to take a different while coming back than he did while going?
Ans.870
Sorry above ones are the correct answers but I don't understand the logic behind that.