Permutation & Combination

Quantitative Aptitude ( CCS) Mathematics - All Exams

Title

45:30

8 of 24 completed

5 of 15 completed

38 of 100 completed

8 of 20 completed

Indian Economy - Understanding the basics of Indian economic system

¹²C₄ + ¹²C₅ = ?

¹³C₅

¹²C₅

¹²C₉

²⁴C₉

12! 12! 12! 12! 8
------- + --------- = -------- + ------------ × ---
4!×8! 5!×7! 4!×8! 5×4!×7! 8

12! 12!×8 12!
= -------- + ------------- = --------- × (1 + 8/5)
4!×8! 5×4!×8! 4!×8!

= (12! × 13)/5!×8! = 13!/5!×8! = ¹³C₅ or ¹³C₈