Let m denote the number of four digit numbers such that the left most digit is odd, the second digit from left is even and all four digits are different and n denotes the number of four digit numbers such that the left most digit is even, an odd second digit from left and all four different digits. If m = n k then the value of k equals

Question

Let m denote the number of four digit numbers such that the left most digit is odd, the second digit from left is even and all four digits are different and n denotes the number of four digit numbers such that the left most digit is even, an odd second digit from left and all four different digits. If m = n k then the value of k equals (A) (6/5) (B) (4/3) (C) (5/4) (D) (3/2)

Tardigrade Admin · Accepted Answer

m = 5 Â· 5 Â· 8 Â· 7 = 1400 n = 4 Â· 5 Â· 8 Â· 7 = 160 Â· 7 = 1120 k =(1400/1120)=(5/4)

$\frac{6}{5}$

$\frac{4}{3}$

$\frac{5}{4}$

$\frac{3}{2}$

$m = 5 \cdot 5 \cdot 8 \cdot 7$
$= 1400$
$n = 4 \cdot 5 \cdot 8 \cdot 7 = 160 \cdot 7 = 1120$
$k = \frac{1400}{1120} = \frac{5}{4}$

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34​

45​

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m=5⋅5⋅8⋅7 =1400 n=4⋅5⋅8⋅7=160⋅7=1120 k=11201400​=45​

$\frac{6}{5}$

$\frac{4}{3}$

$\frac{5}{4}$

$\frac{3}{2}$

$m = 5 \cdot 5 \cdot 8 \cdot 7$
$= 1400$
$n = 4 \cdot 5 \cdot 8 \cdot 7 = 160 \cdot 7 = 1120$
$k = \frac{1400}{1120} = \frac{5}{4}$