Q: How many numbers less than 20 are nonzero multiples of both 2 and 3?

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As numbers get larger, it is more likely that they will be multiples of something.

There are 3 such numbers: 30, 60, 90.

When one of the numbers is positive and the other is negative.

-- both are positive numbers -- both are greater than 15 -- both are less than 1 googol -- both are even numbers -- both are written with one odd digit and one even digit -- both are powers of 2 -- both have the factors (are multiples of) 1, 2, 4, 8, and 16

14. Assuming dealing with only counting numbers (ie integers greater than 0): Numbers divisible by 5 or 7 are their multiples. 50 ÷ 5 = 10 → last multiple of 5 less than 50 is 9 x 5 → 9 numbers less than 50 are divisible by 5 50 ÷ 7 = 71/7 → last multiple of 7 less than 50 is 7 x 7 → 7 numbers less than 50 are divisible by 7 Numbers divisible by both are those which are multiples of their lowest common multiple = 35 50 ÷ 35 = 115/35 → last multiple of 35 less than 50 is 1 x 35 → 1 number less than 50 is divisible by both 5 and 7 and needs to be removed from both the above counts. → (9 - 1) + (7 - 1) = 14 numbers less than 50 are divisible by 5 or 7 but not both. If there is no restriction on numbers being greater than 0, there are infinitely many numbers as it includes the infinite number of negative numbers which are all less than 50 and provide an infinite number of numbers divisible by 5 or 7 but not both.

Related questions

All nonzero numbers have an infinite amount of multiples.

Squares numbers are positive numbers. So that the square numbers less than 100 are 1, 4, 9, 16, 25, 36, 49, 64, and 81, and only 16 and 64 are multiples of 8. Thus, Greta picked 16, and 64.

There are eleven such numbers.Get the common multiple of those numbers. All other common multiples will be multiples of this common multiple; that is, you can multiply the common multiple by 1, by 2, by 3, etc. to get additional numbers that are multiples of both numbers.

15, 30, 45, 60

109 whole numbers greater than 9 and less than 999 are multiples of 9

As numbers get larger, it is more likely that they will be multiples of something.

3. All other multiples of 3 are not prime.

There are 3 such numbers: 30, 60, 90.

When one of the numbers is positive and the other is negative.

-- both are positive numbers -- both are greater than 15 -- both are less than 1 googol -- both are even numbers -- both are written with one odd digit and one even digit -- both are powers of 2 -- both have the factors (are multiples of) 1, 2, 4, 8, and 16

Prime and odd numbers

The multiples of 5 that are also multiples of 6 are multiples of their LCM. The LCM of 5 and 6 is 30, so the question becomes which multiples of 30 are less than 100? The solution is the numbers: 30, 60, 90