CA Foundation · Quantitative Aptitude · Permutations and Combinations
A firm in Hyderabad must form a team of 5 from 7 managers and 4 analysts, such that the team has exactly 3 managers. In how many ways can this be done?
There are 210 ways. Choose 3 managers from 7 in 35 ways, and the remaining 2 places from 4 analysts in 6 ways. Multiplying 35 by 6 gives 210, since the choices are independent and both must be made.
- A210Correct
- B350
- C245
- D126
Explanation
Exactly 3 managers and so 2 analysts: 7C3 × 4C2 = 35 × 6 = 210. Using 7C3 × 4C3 = 140 or counting 'at least' cases would give other values; 350 is 7C3 × 10 which is wrong.
Did you get it right without looking?
One question tells you little. A timed set on Permutations and Combinations shows your real accuracy, how long you take and where you lose marks.
More Permutations and Combinations questions
- From 7 Indian batsmen and 5 bowlers, a team of 6 is to be chosen with exactly 3 batsmen. Rahul, a batsman, must be in the team. In how many …
- If (n + 1)! = 30 × (n − 1)!, what is the value of n?
- A traveller can go from Delhi to Jaipur by 3 train routes or 2 bus routes. From Jaipur to Udaipur there are 4 train routes and 3 bus routes.…
- A restaurant in Hyderabad offers 4 starters, 5 main courses and 3 desserts. A customer orders one starter, one main course and one dessert. …
- A student must answer 6 questions out of 10 in a paper, and must choose at least 4 from the first 5 questions. In how many ways can the stud…
- If nP2 = 90, what is the value of n?