A) 3
B) 4
C) 5
D) 8
Correct Answer: A
Solution :
\[^{15}{{C}_{3r}}{{=}^{15}}{{C}_{r+3}}{{\Rightarrow }^{15}}{{C}_{15-3r}}{{=}^{15}}{{C}_{r+3}}\] \[\Rightarrow 15-3r=r+3\Rightarrow r=3\].
You need to login to perform this action.
You will be redirected in
3 sec
