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A five digit number is to be formed using each of the digits
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28 Sep 2020, 02:49
28 Sep 2020, 02:49
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Question Stats:
68% (01:15) correct
31% (01:26) wrong based on 35 sessions
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A five digit number is to be formed using each of the digits 1, 2, 3, 4, and 5 exactly once. How many such numbers are there in which the digits 1 and 2 are not next to each other?
A. 36
B. 48
C. 60
D. 72
E. 120
A. 36
B. 48
C. 60
D. 72
E. 120
Re: A five digit number is to be formed using each of the digits
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28 Sep 2020, 02:49
28 Sep 2020, 02:49
Expert Reply
Post A Detailed Correct Solution For The Above Questions And Get A Kudos.
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Re: A five digit number is to be formed using each of the digits
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28 Sep 2020, 05:07
28 Sep 2020, 05:07
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total no of five digit numbers formed by using each of the digits 1, 2, 3, 4, and 5 exactly once =5!=120
no of five digit numbers formed by by using each of the digits 1, 2, 3, 4, and 5 exactly once and 1,2 are together in each of digits =4!*2!(here 2! because 1,2 can be arrranged in 2! ways) =48
now no of 5 digit numbers formed by using each of the digits 1, 2, 3, 4, and 5 exactly once and 1,2 are not together in each of digits =120-48=72
so the correct option is D
no of five digit numbers formed by by using each of the digits 1, 2, 3, 4, and 5 exactly once and 1,2 are together in each of digits =4!*2!(here 2! because 1,2 can be arrranged in 2! ways) =48
now no of 5 digit numbers formed by using each of the digits 1, 2, 3, 4, and 5 exactly once and 1,2 are not together in each of digits =120-48=72
so the correct option is D
