Table of Contents
- 1 How many natural numbers less than 10 8 Are there whose sum of digits equals 7?
- 2 How many natural numbers less than 1000 have the sum of their digits equal to 5?
- 3 What is the total number of natural numbers which are smaller than 10,000 and have their all the digits different?
- 4 How many two digit numbers are there whose sum of digits is 10?
How many natural numbers less than 10 8 Are there whose sum of digits equals 7?
The numbers have 8 places (some of which might be zero), and there are 7 units of value to go into them. (Each place can have at most 9 units, but that’s automatic since there’s only 7 units total.) So it’s a stars and bars problem with 7 stars and 7 bars, making (147)=3432 such numbers.
How many natural numbers less than 1000 have the sum of their digits equal to 5?
There are thus in all 21 natural numbers <1000 whose digits sum up to 5, viz. (in increasing order) 5, 14, 23, 32, 41, 50, 104, 113, 122, 131, 140, 203, 212, 221, 230, 302, 311, 320, 401, 410, 500.
How many natural numbers that are less or equal to 1000 and that are not multiples of 3 5 7 or exist?
Totally we have 1000 numbers. One third of them is multilply of 3 (333 numbers), one fifth are multilply of 5 (200 numbers), 1/7 is multilply of 7 (142) numbers.
How many natural numbers have their cubes less than 10,000?
from 1 to 21… numbers have cubes less than 10000.
What is the total number of natural numbers which are smaller than 10,000 and have their all the digits different?
We observe that we can place any one of the 8 digits at units, tens and hundreds place (Repetition allowed). However, 0 can’t be placed at thousands place. So, we can have any one of the 7 numbers at the thousands place. Hence, there are 4096 numbers less than 10000 which can be formed from the given digits.
How many two digit numbers are there whose sum of digits is 10?
Description for Correct answer: Let the two-digit number be 10x + y. Therefore, Required number is 73.
How many natural numbers are there less than 1000?
Numbers less than $1000$ are one digit numbers, two digit numbers and three digit numbers. Therefore, the correct answer is option $a$. Note: There are total 999 natural numbers under 1000 in which we have 261 no.’s where 2 digits are repeated which includes numbers like 11,22,33,44,100, 101, 110,200, 202,220 etc.
How many natural numbers are there from 1 to 1000?
The number of natural numbers from to 1 to 1000 which have none of the digits repeated is 691.