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How many numbers from 100 to 999 inclusive have one digit which is the average of the other two?
Wiki User
∙ 12y ago
45, of which 9 are of the form nnn.
The options are (a) 121 (b)117 (c) 112 (d) 115 (e) 105.
It's out of those answers. If you're like me and retrieved this question off the Australian Maths Competition than you probably already know the options. Surprisingly this question stumped me. However I will try and work it out.
Wiki User
∙ 12y ago
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What are the four digit numbers you can make out of 0-9?
9
What is the square root of all the square numbers between 1 and 300?
There are 16 square numbers between 1 and 300: 2 to 17 inclusive. There is no square root of these numbers: only of their sum or product or average or some other operation.
How many different numbers between 250 and 400 have '2' as the tens digit?
That would be the numbers in the form "32x" (where "x" can be any digit). In other words, ten numbers.
Do all composite numbers end in 2?
No, there are composite numbers that end in every other digit.
How many 7 digit telephone numbers can be formed the first digit cannot be zero?
9,000,000 if there are no other requirements.
What are the four digit numbers you can make out of 0-9?
9
How to do 3 digit division?
Yes. By 1 digit, 2 digit and some even by other 3 digit numbers.
What is the square root of all the square numbers between 1 and 300?
There are 16 square numbers between 1 and 300: 2 to 17 inclusive. There is no square root of these numbers: only of their sum or product or average or some other operation.
How many different numbers between 250 and 400 have '2' as the tens digit?
That would be the numbers in the form "32x" (where "x" can be any digit). In other words, ten numbers.
How many 2 digit numbers have one digit that is twice the other?
Eight (8) of them do.They are1221243642486384 .
Do all composite numbers end in 2?
No, there are composite numbers that end in every other digit.
How many 7 digit telephone numbers can be formed the first digit cannot be zero?
9,000,000 if there are no other requirements.
How can you divide two four digit numbers by each other?
Yes.
How many four digit number are there between 999 and 3000?
1000 - 2999 inclusive.2000. It's inclusive, so you must add 1 to the difference.-----------------------------Number of whole numbers = last number - first number + 1The first 4 digit number is 1000The last depends upon whether the "between" is:exclusive: the "between" is "strictly between", ie the numbers under consideration are greater than the first and less than the second; the 3000 is excluded as it is not less than 3000. This is an understanding that comes from placing a third object between two other objects - you cannot place it on top of one of the other objects as it would not be between them;inclusive: the "between" includes the end numbers, ie the numbers under consideration are greater than or equal to the first number and lest than or equal to the second number; the 3000 is included as it is equal to 3000.If exclusive:The last number is 2999 → number of numbers between 999 and 3000 = 2999 - 1000 + 1 = 2000If inclusive:The last number is 3000 → number of numbers between 999 and 3000 = 3000 - 1000 + 1 = 2001--------------------------------------------------------------------------------Numbers are not necessarily whole numbers; four digit numbers also include 999.1, 999.2, ..., 999.9 which mean there could be an extra 9 four digit numbers between 999 and 3000.999.0 wouldn't normally be written with the zero as it makes no different to the value of the number, however if 998.99 was rounded to 4 significant figures the result would be 999.0 with 4 digits, so 999.0 could be claimed to be a four digit number, which would then either be included or not depending upon whether the between is inclusive or exclusive.
How many three-digit counting numbers are not multiples of 2?
The 3-digit counting numbers are 100 through 999 = 900 numbers.Half them are multiples of 2 (even numbers).The other half are not . . . 450 of them.
The average of six numbers is 4 If the average of two of those numbers is 2 what is the average of the other four numbers?
5
How many five digit numbers are even?
Half of them. Every other number from 0 to 99998 is even. Since there are 90,000 five digit numbers, that means that 45,000 of them are even.
