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Maths Puzzle
How many numbers between 200 and 1200 can be formed with digits 0,1,2,3(repetition of digits not allowed)?
OPTIONS-
a)6
b)8
c)2
d)14
Read Solution (Total 2)
-
- B/w 200 and 1200, there are both 3 and 4 digit numbers.
1) 3 digit numbers:-
The numbers must be greater than 200
=> 1st digit = 2 or 3 i.e 2 ways
=> 2nd digit = 3 ways
=> 3rd digit = 2
=> 2x3x2 = 12 numbers are of three digits
2) 4 digit nos:-
1st digit can onlly be 1 => 1 way
2nd digit = 0 => 1 way
3rd digit = 2,3 => 2 ways
4th digit = 1 way
=> 1x1x2x1 = 2 numbers possible for 4 digits.
Therefore, 12 + 2 = 14 numbers possible
- 12 years agoHelpfull: Yes(11) No(4)
- 0,1,2,3 For 200 2 should be first place. there is only one way to put 2 at first place so 1*remaining digits!=>1*3*2=6 ok
now same for 3 bcs 3 is available in digits. so 1*3*2=6 now
above 1000 we can make only 1 should be first digits means only one way,0 should be second digits means only one way and remaining! =>1*1*2=2
total of all 6+6+2=14 if this is not clear then u can put ur comment below this question i will try to explain again.thanku
- 10 years agoHelpfull: Yes(0) No(1)
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