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Numerical Ability
Permutation and Combination
How many number plates are possible with 1,2,3,4,5(repetition is not allowed)
Ans : 325
Read Solution (Total 4)
-
- There can be 1 or 2 or 3 or 4 or5 digits in a number plate..
for 1 digit number plate possibilities = 5
for 2 digit number plate possibilities = 5*4 = 20
for 3 digit number plate possibilities = 5*4*3 = 60
for 4 digit number plate possibilities = 5*4*3*2 = 120
for 4 digit number plate possibilities = 5*4*3*2*1 = 120
so, total possibilities = 5+20+60+120+120 = 325 - 10 years agoHelpfull: Yes(70) No(0)
- There can be 1 or 2 or 3 or 4 or 5 digits in a number plate..
for 1 digit number plate possibilities = 5
for 2 digit number plate possibilities = 5*4 = 20
for 3 digit number plate possibilities = 5*4*3 = 60
for 4 digit number plate possibilities = 5*4*3*2 = 120
for 5 digit number plate possibilities = 5*4*3*2*1 = 120
so, total possibilities = 5+20+60+120+120 = 325 - 10 years agoHelpfull: Yes(13) No(0)
- there wil be number plates of(5 digit,4 digit,3 digit ,2 digit,1 digit)....so possibilities are((5*4*3*2*1=120)+(5*4*3*2=120)+(5*4*3=60)+(5*4=20)+(5)==325))
- 10 years agoHelpfull: Yes(5) No(0)
- n P r = n!/(n-r)! = 5 P 5 = 5!/0! =120
5 P 4 = 5!/1! = 120
5 P 3 = 5!/2! = 60
5 P 2 = 5!/3! = 20
5 P 1 = 5!/4! = 5
hence,
no. of digits formed = 5 P 5 + 5 P 4 + 5 P 3 + 5 P 2 + 5 P 1
= 120 + 120 + 60 + 20 + 5
= 325 - 10 years agoHelpfull: Yes(5) No(1)
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