Q. Consider the following statements : 1.These are 12 points in a plane of which only 5 are collinear, then the number of straight lines obtained by joining these points in pairs is $\ ^{12}C_{2} - \ ^{5}C_{2}$ ${2.}^{n + 1}C_{r} - \ ^{n - 1}C_{r - 1} = \ ^{n}C_{r} + \ ^{n}C_{r - 2}$ 3.Three letters can be posted in five letter boxes in $3^{5}$ways. Which of the statements given above is/are correct?
A) Only (1)
B) Only (2)
C) Only(3)
D) None of these
Explanation
The correct answer is Option D: None of these.
A detailed explanation for this question is being prepared.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.