Permutation and Combination - Discussion Page For Q.261 | Aptitude Questions and Answers | Aptitude Free Online-Tests | LucentBlackBoard

Home > Arithmetic Aptitude > Permutation and Combination > Questions and Answers Discussion

Find the number of even numbers formed using all the digits 1,2,3,4,5 when each digit occurs only once in each number

A.	6!	B.	2(4!)
C.	5!	D.	4!

Answer and Explanation

Answer:2(4!)

Explanation:
A number is even if its units place is divisible by 2
=> Units place can be filled by either 2 or 4 i.e. in 2 ways
=> The remaining 4 places can be filled by the remaining 4 digits in 4! ways.
=> Total number of even numbers that can be formed = 2(4!) = 48

Comment on this Question
Name:

LucentBlackBoard.com has the web's largest collection of over 15,000 aptitude questions and answers with detailed explanation which include subjects like Arithmetic Aptitude, Logical Reasoning, Verbal Ability, General Knowledge, Programming Skills and more!

Our online education portal provides a unique and standard learning experience for students. We enable the students to prepare for most of the entrance and competitive exams like MBA (MAT, GMAT), Engineering (IIT-JEE, AIEEE, GATE), Employment (IAS, Bank PO, Railway, UGCNET), Civil Services and many more. We bring you the best in education by providing technical excellence and creating innovative solutions. We provide facility for online test preparation that offers 24/7 access to relevant subject matter and relative tests. These test preparations help the students to groom themselves and get prepared before actually facing the examination.