Permutation and CombinationHard
Question
Passengers are to travel by a double decked bus which can accommodate 13 in the upper deck and 7 in the lower deck. The number of ways that they can be divided if 5 refuse to sit in the upper deck and 8 refuse to sit in the lower deck, is
Options
A.25
B.21
C.18
D.15
Solution
upperdeck - 13 seats → 8 in upper deck.
lowerdeck - 7 seats → 5 in lower deck
Remains passengers = 7
Now Remains 5 seats in upper deck and 2 seats
in lower deck
for upper deck number of ways = 7C5
for lower deck number of ways = 2C2
So total number of ways = 7C5 × 2C2 =
= 21
lowerdeck - 7 seats → 5 in lower deck
Remains passengers = 7
Now Remains 5 seats in upper deck and 2 seats
in lower deck
for upper deck number of ways = 7C5
for lower deck number of ways = 2C2
So total number of ways = 7C5 × 2C2 =
= 21Create a free account to view solution
View Solution FreeMore Permutation and Combination Questions
The number of non-negative integral solutions of x1 + x2 + x3 + x4 ≤ n (where n is a positive integer) is...The number of ways in which 6 red roses and 3 white roses (all roses different) can form a garland so that all the white...In how many ways can a pack of 52 cards be divided equally among four players in order to-...The number of words which can be formed from the letters of the word ′BHARATPUR′ so that P,U,R always remain...How many numbers can be formed with the digits 2,3,5,7,0 which are greater than 70,000 (Rept. not allowed) ?...