00:00Here it is giving us in cation, we have 4 digits in our bar 1,2,3,4 and we
00:05Create a 4 digit number from these 4 digit letters.
00:08Then how many 4 digit numbers are there in the bar in which at least 1 digit is repeated?
00:14Wow
00:14Such as 1,1 should occur twice instead of 1, 2 should occur instead of 1, at least one digit
00:20So it should be repeated, that is, it should appear more than once.
00:24So first of all we find the total number of these 4 digits, then the number for
00:30How many digit numbers will be made?
00:32So there are 4 places, there will be 4 at the foot of the plate also, any one of 1, 2, 3, 4
00:38It may come,
00:39There are 4 holes at the foot of the second plate, 4 at the foot of the third plate and 4 at the foot of the fourth plate.
00:44Is,
00:45Now let this multiply, in that case, 1, 1, 1, 2, 1, 3, 1, 4, like this 2, 1,
00:512, 2, 2, 3, 2, 4,
00:53With this time these two have 16, there will be one more in this, one after one in 1, 16,
01:0216 after one in 2, 16 after one in 3, 16 after one in 4,
01:06So here I keep multiplying, so 4, 4 da 16, 16, 4 da 64, and 64, 4
01:13Da is 256, 256 is the total number.
01:20Now if we subtract that from the total number, then there is not a single repeat in it, so fart.
01:26What should I tell you?
01:28The repeat ones, there should not be a single repeat later, so how many numbers will there be?
01:33So if there is not a single repeat, then how many 140s will be there in the foot of the 1st place?
01:37Four to one number can come as a subscriber or that number can be called
01:48We will double the distance and the cheek will be closed and we will do the same if you subscribe
02:03How many times will there be one repetition without one repetition? 24 So if we subtract 24 from 256
02:12If we give it then in our part we want that number which has one repetition i.e. 256 minus 24 i.e.
02:20232
