Question
Question: How many numbers can be made with the help of the digits 0, 1, 2, 3, 4, 5 which are greater than 300...
How many numbers can be made with the help of the digits 0, 1, 2, 3, 4, 5 which are greater than 3000 (repetition is not allowed)
A
180
B
360
C
1380
D
1500
Answer
1380
Explanation
Solution
All the 5 digit numbers and 6 digit numbers are greater than 3000. Therefore number of 5 digit numbers
= 6P5−5⥂P5=600.
{Since the case that 0 will be at ten thousand place should be omit}. Similarly number of 6 digit numbers 6 ! – 5 ! = 600.
Now the numbers of 4 digit numbers which are greater than 3000, having 3, 4 or 5 at first place, this can be done in 3 ways and remaining 3 digit may be filled from remaining 5 digits i.e., required number of 4 digit numbers are
5P3×3=180.
Hence total required number of numbers = 600 + 600 + 180 = 1380.