On a railway there are 20 stations. The ...

On a railway there are 20 stations. The number of different tickets required in order that it may be possible to travel from every station to every station is

A

210

B

225

C

196

D

105

Text Solution

Verified by Experts

The correct Answer is:

A

Number of different tickets
=20+19+18+17+ . . .+3+2+1=210

Promotional Banner

Promotional Banner

Topper's Solved these Questions

PERMUTATIONS AND COMBINATIONS
ARIHANT MATHS|Exercise Exercise (More Than One Correct Option Type Questions)|10 Videos
PERMUTATIONS AND COMBINATIONS
ARIHANT MATHS|Exercise Exercise (Passage Based Questions)|15 Videos
PERMUTATIONS AND COMBINATIONS
ARIHANT MATHS|Exercise Exercise For Session 7|5 Videos
PARABOLA
ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|36 Videos
PROBABILITY
ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|55 Videos

Similar Questions

Explore conceptually related problems

On a railway route there are 20 stations. What is the number of different tickets required in order that it may be possible to travel from every station to every other station

On a raiway there are 10 stations. The number of types of tickets required in order that it may be possible to book a passenger from every staton to every other is

There are 10 railway stations between a station X and another station Y. Find the number of different tickets that must be printed so as to enable a passenger to travel from one station to any other.

There are 50 stations on a railway line.The number of different kinds of single 2 nd class tickets must be printed so as to enable a passenger to travel from one station to another station is:

There are 15 stations from New Delhi to Mumbai. How many first class tickets can be printed to travel from one station to any other station?

In a network of railways,a small island has 15 stations.Find the number of different types of tickets to be printed for each class,if every stations must have tickets for other stations.

There are n stations on a railway line. The number of kinds of tickets printed (no return tickets) is 105. Find the number of stations

ARIHANT MATHS-PERMUTATIONS AND COMBINATIONS -Exercise (Single Option Correct Type Questions)

The number of numbers less than 1000 than can be formed out of the dig...
Text Solution
|
If the permutations of a, b, c, d, e taken all together be written dow...
Text Solution
|
On a railway there are 20 stations. The number of different tickets re...
Text Solution
|
A is a set containing n elements. A subset P of A is chosen at random....
Text Solution
|
The straight lines I(1),I(2),I(3) are paralled and lie in the same pla...
Text Solution
|
Let A be a set of n (>=3) distinct elements. The number of triplets (x...
Text Solution
|
The total number of five-digit numbers of different digits in which...
Text Solution
|
The total number of words that can be formed using all letters of the ...
Text Solution
|
A man has three friends. The number of ways he can invite one frien...
Text Solution
|
The number of three digit numbers of the form xyz such that x lt y , z...
Text Solution
|
The letters of the word 'MEERUT' are arranged in all possible ways as ...
Text Solution
|
The number of ways in which 10 condidates A(1),A(2),......,A(10) can b...
Text Solution
|
Let A be the set of 4-digit numbers a1 a2 a3 a4 where a1 > a2 > a3 > a...
Text Solution
|
Find the number of distinct rational numbers x such that o<x<1a n dx=p...
Text Solution
|
The total number of positive integral solutions for (x, y, z) such tha...
Text Solution
|
ABCD is a convex quadrilateral and 3, 4, 5, and 6 points are marked...
Text Solution
|
In how many ways can a team of 6 horses be selected out of a stud o...
Text Solution
|
The number of polynomials of the form x^(3)+ax^(2)+bx+c that are divis...
Text Solution
|
Let x(1),x(2),x(3), . . .,x(k) be the divisors of positive integer 'n'...
Text Solution
|
The total number of function f from the set (1,2,3) into the set (1,2,...
Text Solution
|