Q. 635.0( 2 Votes )

# Using the digits 1, 2, 3, 4, 5, 6, 7, a number of 4 different digits is formed. Find

Answer :

Given:-total number of digit to be form=4

=^{7}P_{4}=840

Number which are ending with 2

^{6}P_{3}=120

Number which are ending with 4

^{6}P_{3}=120

Number which are ending with 6

^{6}P_{3}=120

how many numbers are exactly divisible by 2=120+120+120=360

=40

The number which last two digit divisible by 4

Are 12,16,24,32,36,44,52,56,64,72,76

^{11}P_{2}.^{5}P_{2}

=200

Answer is above in table

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