Elitmus
Exam
Numerical Ability
Permutation and Combination
In how many a sandwich of four layer can be formed using four color red,yellow,blue,white such that no two layer are of same color.
Read Solution (Total 23)
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- as all the colors are different, so two layer will not be of same color
no. of ways = 4P4 = 4! = 24 - 10 years agoHelpfull: Yes(51) No(26)
- Ans: 4*3*3*3=108
- 10 years agoHelpfull: Yes(49) No(6)
- 1) for no two layer are of same color
ans) 4p4 or 4!
2)No two adjacent layer are of the same.
ans) 4*3*3*3
explanation :- for 1st layer we have 4 colors.
for 2nd layer we have 3 colors left as we cannot use the color used in 1st layer.
for 3rd layer we cannot use the color used in 2nd layer but we can use the color used in 1st layer so again we got 3 choices.
same goes for 4rth layer .
- 10 years agoHelpfull: Yes(43) No(0)
- I think it is 108 ways..4C1 * 3C1 * 3C1 * 3C1 when n two adjacent layers can have the same color.
- 10 years agoHelpfull: Yes(6) No(1)
- no 2 layers are same:
4*3*2*1
no adjacent layer are same:
4*3*3*3
- 10 years agoHelpfull: Yes(6) No(0)
- No of ways = 4!= 24
because we have to arrange 4 different things. so it will be 4P4 = 4!=24
@KOLLIKISHORE : We use COMBINATION in case of identical things and use PERMUTATION in case of different objects - 10 years agoHelpfull: Yes(5) No(2)
- 108
4*3*3*3 - 10 years agoHelpfull: Yes(2) No(3)
- 4*3*2*1
=24 - 10 years agoHelpfull: Yes(2) No(0)
- 4c1+4c2+4c3+4c4=15 ways. am i correct?
- 10 years agoHelpfull: Yes(1) No(15)
- i think it may be 67
- 10 years agoHelpfull: Yes(1) No(2)
- 4P4=!4
=24 - 10 years agoHelpfull: Yes(1) No(1)
- keep one layer red then rest 3 can be arranged in 3!=6
keep one layer yellow then rest 3 can be arranged in 3!=6
keep one layer blue then rest 3 can be arranged in 3!=6
keep one layer white then rest 3 can be arranged in 3!=6
so total ways=6+6+6+6 =24
- 10 years agoHelpfull: Yes(1) No(0)
- assume 4 blocks and assume 1,2,3,4.
1st can be fill by 4 ways (1/2/3/4)(assume 1 is at 1st)
2nd can be by 3 ways (2/3/4 can be)(assume 2 is at 2nd)
3rd can be by 3 ways (1/3/4 can be)(assume 3 is at 3rd)
4th can be by 3 ways (1/2/4 can be)
So Total=4*3*3*3=108 - 10 years agoHelpfull: Yes(1) No(0)
- as their are 4 layer so this can be done by :4x3x2x1=24
- 10 years agoHelpfull: Yes(1) No(0)
- If repitition is allowed...(as it is the ques of repition allowed)
there will be 4*4*4*4=256 ways
for 2 colors to be same there are chances
consecutive 2 places with same colour in 3 ways+consecutive 3 places with same colour in 2 ways+consecutive 4 places with same colour in 1 way=6 ways
now we have 4 colours so 4*6=24
no two layers having same colours is 256-24=232 - 9 years agoHelpfull: Yes(1) No(0)
- Sorry...a little bit change in the statement....actually it was...
No two adjacent layer are of the same. - 10 years agoHelpfull: Yes(0) No(0)
- acc to me 109 ways... wats the answer?
- 10 years agoHelpfull: Yes(0) No(4)
- i did not remember options but one was 48 nd other 108...i think so....but what will be answer if two adjacent layer can not be of same color....
- 10 years agoHelpfull: Yes(0) No(0)
- 4*3*2*1=24 ways
- 10 years agoHelpfull: Yes(0) No(0)
- for 1st layer we have 4 choice and for 2nd layer 3 likewise
it will be 4*3*2*1 or else we can say 4!
so ans is ..24 - 10 years agoHelpfull: Yes(0) No(0)
- for the first place we have 4 choice and second three as so on
we get 24 - 10 years agoHelpfull: Yes(0) No(0)
- - - - - , the dashes show the different four layers in which first can be filled with four(red, yellow, blue, white), similarly second can be filled with 3 layers and 2 for third layer and 1 for last layer i.e.
4*3*2*1 = 24 - 10 years agoHelpfull: Yes(0) No(0)
- 4*3*3*3 bcz after putting 1st we hv 3 so ....3,3,3
- 10 years agoHelpfull: Yes(0) No(0)
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