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Numbers divisible by 9 have the sum of their digits equal to 9 or a multiple of 9. A number divisible by 2 is an even number. If a 3 digit number is 42n then n can only be 3 if the number is divisible by 9 and 423 is not within the specified range. If a 3 digit number is 43n then n must be 2 for it to be divisible by 9.. The number is thus 432 and this is even and so divisible by 2. If the 3 digit number is 44n then n must be 1 and 441 is odd and not divisible by 2. The only valid solution is 432.
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Let three consecutive integers be n, n+1 and n+2. If n is divisible by 3 then n+1 and n+2 cannot be divisible by 3 as these numbers will respectively leave remainders of 1 and 2. If n is not divisible by 3 then it will leave a remainder of 1 or 2. If n leaves a remainder of 1, then n+1 leaves a remainder of 2 and n+2 is therefore divisible by 3. If n leaves a remainder of 2, then n+1 is divisible by 3 and n+2 is not divisible by 3 as it leaves a remainder of 1.
Any multiple of 9. In other words, any number of the form 9 * n. Add the digits of the number. If that total is divisible by nine, so is the original number. Example: 12,345,678. The digits total 36. 36 is divisible by 9. So is 12,345,678.
3 and 9. 93 has a digit sum of 12, initially, which is divisible by 3, but not by 9. So 93 is divisible by 3, but not by 9. 99 has a digit sum of 18, initially, which is divisible by 3 and 9. So 99 is divisible by both 3 and 9.
Numbers divisible by 9 have the sum of their digits equal to 9 or a multiple of 9. A number divisible by 2 is an even number. If a 3 digit number is 42n then n can only be 3 if the number is divisible by 9 and 423 is not within the specified range. If a 3 digit number is 43n then n must be 2 for it to be divisible by 9.. The number is thus 432 and this is even and so divisible by 2. If the 3 digit number is 44n then n must be 1 and 441 is odd and not divisible by 2. The only valid solution is 432.
n = 1, 3 or 9.
That works with 3 and 9.
This works with 3, and with 9.
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The units digit of 9n is 9 if n is odd and 1 if n is even. So 1.
(The assumes that "the number" in the question is not n, although if they are they same number, this is still true.) "If the sum of the digits of the number is divisible by n, then the number itself is divisible by n" is true if n is 3 or if n is 9.
You can find the answer of this question using A.P.(Arithmetic Progression). Its the easiest way. Here's the solution: First 2-digit no. divisible by 3 = 12 Second 2-digit no. divisible by 3 = 15 Last 2-digit no. divisible by 3 = 99 Hence, the 2-digit no.s divisible by 3 form an A.P. with common difference 3 as follows: 12,15,.........................,99 Here, a (First term) = 12 l (Last term) = 99 d (Common difference) = 3 n (No. of terms) = ? Using the formula, l = a + (n-1)d 99 = 12 + (n-1)3 (n-1)3 = 99 - 12 (n-1)3 = 87 n-1 = 87 / 3 n-1 = 29 n = 29 + 1 = 30 Hence, the total no. of 2-digit no.s divisible by 3 are 30.
I go for 9,876,545,640 Can't say I am certain, though.
If n is divisible by both 5 and 6, then it should be divisible by 30 (5 * 6). Considering you are asking for only two-digit numbers, the answer(s) would be 30, 60, and 90. So, three numbers.
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