How many 4 digit numbers less than 7000 can be formed such that the number is odd
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374375372250 Show
Answer : A Solution : Using the digits 0, 1, 3, 7, 9 (`because 0` can not come in 1st box) number of three digit natural numbers that can be formed = 100 and number of four digit natural numbers less than 7000, that can be formed = 250 (`because` only 1 or 3 can come in 1st box) `therefore` Total number of natural numbers formed = 4 + 20 + 100 + 250 = 374
Question 299130: How many four-digit odd numbers less than 6000 can be formed using the digits 2,4,6,7,8,9? Answer by Edwin McCravy(19249) You can put this solution on
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2,4,6,7,8,9
We choose the fourth digit first: There are 2 ways to select the fourth
digit, either 7 or 9, so that the number will be odd.
Next we choose the first digit: There are 2 ways to select the fourth
digit, either 2 or 4, so that the number will be less than 6000.
Next we choose the second digit: There are 4 ways to select the second
digit, any of the four remaining digits.
Finally we choose the third digit: There are 3 ways to select the second
digit as any of the three remaining digits.
So the number of such four-digit numbers is 2*2*4*3=48
Here they all are:
2467 2469 2479 2487 2489 2497
2647 2649 2679 2687 2689 2697
2749 2769 2789 2847 2849 2867
2869 2879 2897 2947 2967 2987
4267 4269 4279 4287 4289 4297
4627 4629 4679 4687 4689 4697
4729 4769 4789 4827 4829 4867
4869 4879 4897 4927 4967 4987
EdwinSolution The correct option is C 374Natural numbers less than 7,000, means first number can not be greater than 6. There are four positions to fill. ∴ There are 3 ways to fill the first position and there are 5 ways to fill the remaining positions. Hence, required number =3×5×5×5−1(∵0000 is not included) =374How many 4Here, the required numbers are greater than 7000. Therefore, the thousand's place can be filled with any of the 3 digits: 7, 8, 9. Thus, the total number of possible outcomes is 3C1 × 4C1 × 3C1 × 2C1 = 3 × 4 × 3 × 2 = 72.
How many four digit odd numbers less than 6000 can be formed using?144 four-digit odd numbers less than 6000 can be formed using the digits given.
How many 4So overall there are 3×5×4×3=180 numbers.
How many 4The thousands place in a 4-digit number cannot be 0. The smallest 4-digit number is 1000 and the greatest 4-digit number is 9999. There are 9000 four-digit numbers in all.
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