Please answer the following question:A and B pick up a card at random from a well schufle pack of cards,one after the another,replacing it every time till one gets a heart.If A beins the game then the probability of B ends the game is :1) 2/7 2)4/7 3)3/4 4)1/4 5)none of these
If A starts the game, and B ends it, that means whatever be the number of times they pick it up, A never got hearts and B got the heart at the end.
If it was just two pick ups then Probability of that is (A didn't get hearts) followed by (B got hearts)
P = (3/4)*(1/4)
If it took four chances, P = (3/4)*(3/4)*(3/4)*(1/4) .. which basically means that in the previous three chances no one got a heart.
so, this way it may go on till infinity...
So, final probability of these mutually exclusive events will be the summation of all these probabilities.
There are 4 identical oranges, 3 identical mangoes and 2 identical apples in the basket. the number of ways in whihc we can select one or more fruits from the basket is
In an examination , max marks for 3 papers is 50 each and for the fourth is 100 . Find the number of ways in which a student can score 60% aggregate marks .
I still did nt get the part where 3 points on collinear points and point is a non collinear point is mentioned.
See when you select three points on a line, and another point outside somewhere in the space, how can you form a quadrilateral ? So, we need to remove those cases from the total cases.
See when you select three points on a line, and another point outside somewhere in the space, how can you form a quadrilateral ? So, we need to remove those cases from the total cases.
PS: I hate "none of these" option
Thank you @[562114:Budokai001], @[592846:YouMadFellow], @[169132:naga25french]
@sidroy09 said: If all the words formed by letters "RAINBOW" are arranged in a dictionary form,then what is the position of the word RAINBOW in that dictionary?
arrange in ascending order ABINORW
each alphabet will have 6! words
since ABINO are before R , we have 5*6! words
next for R , A is the least so its correctly placed . B should occur next .. but we have I .. so 24 words are taken ..
And if I comes first , next should be B .. so we need to count another 3! ..
Rest all words are in correct position
so intotal 3600 + 24 + 4 = 3630 .. so RAINBOW would be 3631th word
arrange in ascending order ABINORWeach alphabet will have 6! wordssince ABINO are before R , we have 5*6! wordsnext for R , A is the least so its correctly placed . B should occur next .. but we have I .. so 24 words are taken ..And if I comes first , next should be B .. so we need to count another 3! ..Rest all words are in correct positionso intotal 3600 + 24 + 4 = 3630 .. so RAINBOW would be 3631th word
@chillfactor said:Yup my mistake. Thanks for the correction.Lets say that a is the marks lost in one section, b in another, c is third and d in fourth.So, (45 - a) + (45 - b) + (45 - c) + (45 - d) 90a + b + c + d 90So, C(94, 4) ways, but we have counted those cases also when a, b, c, d > 45When a > 45, i.e., a = 46 + a'=> a' + b + c + d 44=> C(48, 4) waysSimilarly for other variablesSo, total number of ways = C(94, 4) - 4*C(48, 4)
Sir:
93C3 hoga and 47C3 hoga which will give 64906 ways.
