[dipsleo88]

In how many ways the word 'PERMUTATIONS' can be arranged such that 4 alphabets stay between the alphabet P and S??

pls do give xplaination to ur solution.

[abhay15783]

[QUOTE=kinscool;1584718]

Originally Posted by pari16

Yup...but clock questions are based normally on the analog clocks.
So i think it should be 1 a.m. on Wednesday.

If it were digital, the clock would have to lose 24 hrs and hence it would show the correct time after 144 hrs i.e. 6 days = Saturday 1 a.m.[/QUOTE]
why is that?

Because then there will be difference between say 12 am and 12 pm

while in analog there is no difference between any time between am or pm

Hence needs to lose 24 hours before it shows correct timing in digital clock

[abhay15783]

Originally Posted by dipsleo88

In how many ways the word 'PERMUTATIONS' can be arranged such that 4 alphabets stay between the alphabet P and S??

pls do give xplaination to ur solution.

Number of ways of selecting the 4 alphabets lying in between P and S
10C4
Arranging s and p=2 ways
Arranging four inside=4!

Arranging after grouping =6!
And for two T's dividing by 2!

hence final answer will be=10C4*6!*4!*2!/2!
=10C4*4!*6!
=10! ( is the answer correct )

Sorry just made the silliest mistake had placed 6! instead of 7!


answer 7*10!
=25401600

[pari16]

Originally Posted by dipsleo88

In how many ways the word 'PERMUTATIONS' can be arranged such that 4 alphabets stay between the alphabet P and S??

pls do give xplaination to ur solution.

the ways in which this can be achieved is :
no of alphabets in the word = 12. remove p&s hence 10.(2 T's)
these 10 alphabets can be arranged in 10!/2! ways.

now places of p & s can be as follows :
1-5 or 2-6 or 3-7 upto 7-12 = 7 options
i.e.(p& s can exchange places) hence-> 7*2!

thus total arrangements = (10!/2!) * 7*2!

[pari16]

Originally Posted by abhay15783

I have delibrately not considered the cases where one T or two T or no T are in between P and S at it wont alter the answer )

i think u have missed the different positions that p & s can take... it need not be only 1 & 5...that gives the multiply by 7 factor.
so (your_ans * 7) will give all arrangements...

[shalabh_mudgal]

In how many ways the word 'PERMUTATIONS' can be arranged such that 4 alphabets stay between the alphabet P and S??pls do give xplaination to ur solution. ======================I think correct answer would be (7*2*!10)/2 = 24501600

[dipsleo88]

Originally Posted by shalabh_mudgal

In how many ways the word 'PERMUTATIONS' can be arranged such that 4 alphabets stay between the alphabet P and S??pls do give xplaination to ur solution. ======================I think correct answer would be (7*2*!10)/2 = 24501600

shalabh u r rite...the answer is 25401600...guess u ve a typo error out der...but please xplain kaise kia gaya???

[pari16]

Originally Posted by dipsleo88

shalabh u r rite...the answer is 25401600...guess u ve a typo error out der...but please xplain kaise kia gaya???

explanation : post #7274

[shalabh_mudgal]

YES ans is 25401600solution is..tied the P and s with a gap of four alphabets= total 7 positionsswitch p with s or vice versa=2 positionsremaining letters are 10=!10ther are 2 t alphabets= divide by 2(7*2*!10)/2=25401600

[shekhar255]

yup it 25401600....