How many three digit numbers are there such that at least one of their digits is 7
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Answer (Detailed Solution Below)Option 2 : 125 Free January Month Current Affair (1st Jan - 15th Jan) 30 Questions 30 Marks 30 Mins The number of odd digit numbers are 5 i.e. 1, 3, 5, 7, 9. So the required number will be formed using only these 5 digits. Let the 3 digit number be “abc” So “a” can be replaced by 5 odd digit numbers i.e. 1, 3, 5, 7, 9 and same with “b” and “c” (The first digit of the number say "a" has 5 choices By using permutation concept the required numbers = 5 × 5 × 5 = 125 ∴ The number of three digit numbers in which all the digits are odd is 125. Last updated on Nov 4, 2022 SSC CHSL 2022 notification will be released on 6th December 2022. Earlier, the notification was scheduled to be released on 5th November 2022. Candidates can log in to their profiles and check individual marks between 26th November 2022 to 16th November 2022. The SSC is going to release the SSC CHSL notification on 6th December 2022 as declared by SSC. Candidates who have completed Higher Secondary (10+2) can appear for this exam for recruitment to various posts like Postal Assistant, Lower Divisional Clerks, Court Clerk, Sorting Assistants, Data Entry Operators, etc. The SSC Selection Process consists of Computer Based Exam, Descriptive Test and Typing/Skill Test. Recently, the board has released the SSC CHSL Skill Test Result for the 2020 cycle. The candidates who are qualified are eligible to attend the document verification. Three digits numbers start from 100 and end at 999. So, the smallest three-digit number is 100 and the largest 3-digit number is 999. In Maths, the number is defined by the number of digits it has. A three-digit number will be described by the place values of its digits. As we know, there are nine single-digit
numbers, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, and ninety two-digits numbers (from 10 to 99). A two-digit number is formed using zero (0) along with a single digit. Now, the three-digit numbers are also formed using these single digits or double digits, along with using zero (0). For example, 809 is a three-digit number, where the place value of 9 is ones, 0 is tens and 8 is hundreds. As we already discussed, the three digits numbers are from 100 (hundred) to 999 (nine hundred ninety-nine).
Before we see the list of three digits numbers, first let us discuss how many three digits numbers we have from 100 to 999. Since, 99 + 1 = 100 And 1000 – 1 = 999 Count of Numbers from 1 to 1000 = 1000 Now excluding single digits, two-digit numbers and 1000 (a four-digit number) from the list of numbers of 1 to 1000, we are left with: 1000 – 99 – 1 = 900 Hence, there are 900 three-digit numbers in total. Numbers up to 3-digits are provided here in the below table.
Place Value of Three-digit NumbersEach digit, in a three-digit number, has its place value. This place value basically represents the location or position of the digit in a number. The position of the digits helps us to determine the value of a number. The digit at the right-most place in a three-digit number is said to be at one’s place or unit place, the middle digit is at ten’s place and the left-most digit is at hundred’s place.
For example, in the number 342, the place values of all the three digits are: Expanded Form of Three Digits NumbersThe three digits numbers say ABC, can be expanded in the form of: ABC = A x 100 + B x 10 + C x 1 Where A, B and C are the three digits. Thus, by this expansion, we can also determine the place value of the digits.
Examples are given below to make you understand better.
Operations on Three Digits NumbersWe can perform all four arithmetic operations on a three-digit number. We should notice the below-given points while adding, subtracting, multiplying and dividing the three-digit numbers.
Video Lesson on NumbersRelated Articles
Frequently Asked Questions on Three Digits NumbersThe smallest 3-digit number is 100 (Hundred). The largest 3-digit number is 999 (Nine hundred ninety-nine). An example of a three-digit number is 721. There is a total of 900 three-digit numbers. How many 3 digit numbers are there in which the sum of digits is 7?28 is the total.
How many 3 digit numbers are there such that at least one of their digits is 6?Thus there are 252 possibilities in total.
How many threeSo, the total number of 3-digit whole numbers that have a 7 or a 9 in them should be: 199 + 199 =398 numbers in total.
How many 3 digit numbers have at least one of their digits as 5?Total = 100 + 80 + 72 numbers = 252 numbers.
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