For a positive integer k written in decimal notation, #(k)

Question

For a positive integer k written in decimal notation, #(k) is defined as the product of the digits of k. For instance, #(333)=27 and #(142)=8. If Y is the set of four digit whole numbers w such that #(w)=60, what percent of the elements of Y are greater than 5000?

lanuk · Answer

25%

The four digist are the factors of 60..so they could be (5322) or (1652) or (1453).
The numbers in each case that are greater than 5000 are 3 of 12, 4 of 24 and 4 of 24...so total 15 of 60 or 25%

iced_tea · Answer

i am getting 21/60

numbers could be permutation of 5322 or 1652 or 1453. 
total numbers = !3/!2 + 2*3*2*1 + !3 = 21

ivymba · Answer

10/21 

 Permutations of 4351 2651 , 2353 = 3 * 4!
Total possible combinations = 9P4 (we have to ignore 0)

3*4!/9P4 * 100 = 10/21

Rayn · Answer

Solution please

I thought 25% as well.

cicerone · Answer

Hey lanuk,

it must be 3 of 12, 6 of 24 and 6 of 24.........so total 15 out of 60 ie 25%.

I too got the same answer. So let's wait for the OA

cicerone · Answer

Hey kevin i got it...............

it is 21/60 ie 35%

lanuk · Answer

Yup Cicerone..you're right..should be 21/60... 3 +12(Both starting with 5 and 6 are greater than 5000) +6 Silly mistake

For a positive integer k written in decimal notation, #(k)

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