MadeEasy Subject Test: Programming & DS - Hashing

Question

Comments

@saxena0612, i got 168 too, but the answer given is 128.

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@ saxena0612 there is no restriction on 91 it can come at any time so 12 and 62 can come after first 3 

i forgot how i solved it but  i think the approach should be than if there are m and n items then the number of ways  we can arrange them such that there own order don't change.  i.e.  (m+n)!/m!.n!

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@ charul please post the solution given for this problem .

Answer 1

lets determine dependencies first

12 comes after 2,13,24 

between 2,13,24 any order is possible

62 comes after 12

77 can come anytime(will calculate at last)

82 comes after 62 and 77

91 can come anytime(will calculate at last)

 

3! for 2,13,24

then 12-62

77 can come anywhere in 6 slots of those 5 numbers

3! * 6

then 82

now 91 can come anywhere in 8 slots

3!*6*8=288

 

dependencies==>

(  (2,13,24)-->12-->62 ) --> 82

77--> 82

91

 

see 77 can come anywhere before 82

91 has zero restrictions

again calculating......

3! then 12-62

77 can come in 6 slots

then 82

91 can come in 8 slots

3!*6*8=288

 

 

please check thoroughly to detect any errors

please check thoroughly to detect any errors

@Bikram@Arjun@saxena0612