TCS
Company
Numerical Ability
Permutation and Combination
1, 4, 2, 8, 6, 24, 22, 88, ?
. How many number plate with 1,2,3,4,5 digits can be created, if repetition of numbers is not allowed?
Read Solution (Total 9)
-
- a) 1*4=4......4-2=2
2*4=8......8-2=6
6*4=24.....24-2=22
22*4=88.......88-2=86
Therefore, answer is 86
b) 5*4*3*2*1 = 120
- 10 years agoHelpfull: Yes(20) No(17)
- for plates with a single no : 5c1
with 2 numbers : 5c2*2!
with 3 numbers : 5c3*3!
with 4 nos : 5c4* 4!
with 5 ns : 5!
add up all these cases - 10 years agoHelpfull: Yes(18) No(1)
- 5 digit no.=5*4*3*2*1=120
4 digit no.=5*4*3*2=120
3 digit no.=5*4*3=60
2 digt no.=5*4=20
1 digit no.=5
total=120+120+60+20+5=325 - 10 years agoHelpfull: Yes(10) No(1)
- 2^5-1=31
5c5+5c1+5c2+5c3+5c4 - 10 years agoHelpfull: Yes(2) No(2)
- plates of one digit 1
+ plates of two digits 2!
+plates of three digits 3!=6
+plates of four digits 4!= 24
+plates of five digits 5!= 120
Total 157 plates.... - 10 years agoHelpfull: Yes(1) No(6)
- 5c1+5c2*2!+5c3*3!+5c4*4!+5! = 210
- 10 years agoHelpfull: Yes(1) No(0)
- 1*4=4......4-2=2
2*4=8......8-2=6
6*4=24.....24-2=22
22*4=88.......88-2=86
ans=86
5!=120 - 10 years agoHelpfull: Yes(1) No(0)
- 1,4,2,8,6,24,22,88,?
ans is 86
1,1*4=4,4-2=2,2*4=8,8-2=6,6*4=24,24-2=22,22*4=88,88-2=86 - 10 years agoHelpfull: Yes(1) No(0)
- giv me d crct sltn
- 10 years agoHelpfull: Yes(0) No(1)
TCS Other Question