Question

A city has 12 gates. In how many ways can a person enter the city through one gate and come out through a different gate?

Solution

Correct option is

132

Since, there are 12 ways to enter into the city. After entering into the city, the man can come out through a different gate in 11 ways. 

Hence, by the fundamental principle of counting. 

Total number of ways is 12 × 11 = 132 ways.

SIMILAR QUESTIONS

Q1

If n is the number of ways in which an examiner can assign 30 marks to 8 questions, giving not less than 2 marks to any quation find n/40.

Q2

Find the number of rectangles that you can find on a chessboard.

Q3

Find the number of integers greater than 7000 that can be formed with the digits 3, 5, 7, 8 and 9, no digit being repeated.

Q4

Ten persons, amongst whom are A, B and C, are to speak at a function. If n is the number of ways in which it can be done if A wants to speak before B, and B wants to speak before C find n/800.

Q5

Find the largest  such that 

      

Q6

Find the largest integer n for which 35! Is divisible by 3n.

Q7

The number of natural numbers which are smaller than 2 × 108 and which can be written by means of the digits and 2 is ………..

Q8

Find the exponent of 2 in 50!?

Q9

Find the number of zeroes in 100!

Q10

Find the number of different words which can be formed using all the letters of the word ‘HISTORY’.