Best Answer

If two digit number can have a repeated digit (eg 44) then there are 20 possible numbers, otherwise there are 16 possible numbers:

There are 4 single digit numbers;

With repeats allowed there are a further 4 x 4 = 16 two digit numbers making a total of 20;

Without repeats allowed there are a further 4 x 3 = 12 two digit numbers making a total of 16.

Q: How many positive integers less than 100 can be written using the digits 3 and 4 and 5 and 6?

Write your answer...

Submit

Still have questions?

Continue Learning about Math & Arithmetic

Fifty

1-digit number: 5 possibilities 2-digits number: 5 x 5 = 25 possibilities So there are 30 numbers.

If a digit can be repeated there are 5 x 5 x 5 = 125 possible numbers If a digit cannot be repeated there are 5 x 4 x 3 = 60 possible numbers.

Using only positive digits, and disregarding their order, 3 ways.

The sum of the first 10 positive integers, using the formula N1 + (N1 + 1) + ... + N2 = N2 * (N2 + 1) / 2 - (N1 - 1) * N1 / 2 is: 55

Related questions

Fifty

125

20. 16 without repeating a digit.

We don't generally consider the negative factors of positive numbers, but they are exactly the same digits as the positive factors, just with minus signs.

No NEETs are counted using positive integers.No NEETs are counted using positive integers.No NEETs are counted using positive integers.No NEETs are counted using positive integers.

1-digit number: 5 possibilities 2-digits number: 5 x 5 = 25 possibilities So there are 30 numbers.

Using two positive integers to add up to 10:1 + 92 + 83 + 74 + 65 + 56 + 47 + 38 + 29 + 1

integers are used in skateboarding by using positive integers like 180 360 540 720 and 900

The set of natural numbers (counting numbers) {1,2,3,4....} corresponds to the positive integers. Note that the number 0 is neither positive nor negative. So anytime you want to count something you use natural numbers, which means you are also using positive integers.

If a digit can be repeated there are 5 x 5 x 5 = 125 possible numbers If a digit cannot be repeated there are 5 x 4 x 3 = 60 possible numbers.

If repeats are permitted: 2 x 5 x 5 = 50 different odd numbers If repeats are not permitted: 2 x 4 x 3 = 24 different odd numbers

Using only positive digits, and disregarding their order, 3 ways.