In how many ways can a team of 6 horses be selected out of a stud of 16, so that there shall always be three out of A B C A B C, but never A A, B B or
In how many ways can a team of 6 horses be
selected out of a stud of 16, so that there shall always be three out of A B C A B C, but never A A, B B or C
C together
a. `840`
b. `1260`
c. `960`
d. `720`
A. 720
B. 840
C. 960
D. 1260
4 views
1 Answers
Correct Answer - C
`because`16 horses=10 horses+(A,B,C,D,E,F)
`therefore`The number of ways`=.^(10)C_(3)xx`(Number of ways of ways of choosing out of A,B,C,D,E,F, so that AD,BE and CD are not together)
`=.^(10)C_(3)xx`(One from each of pairs AD,BE,CF)
`=.^(10)C_(3)xx.^(2)C_(1)xx.^(2)C_(1)xx.^(2)C_(1)=960`
4 views
Answered