4
There are 4500 such numbers.
22 of them.
Four random, positive, one-digit integers.
There are 10 one digit positive integers (0 - 9) and 9 one digit negative integers (-9 to -1) making 19 in all.
18 positive integers and 36 integers (negative and positive)
Add the magnitudes of the integers (-4 has a magnitude of 4), then take the sign to the answer.
4
There are 4500 such numbers.
22 of them.
400/4= 100 and 800/4=200
Four random, positive, one-digit integers.
There are 10 one digit positive integers (0 - 9) and 9 one digit negative integers (-9 to -1) making 19 in all.
-4, -2, 0, and 2 are the four consecutive even integers. When you add them up they equal -4.
There is a clever but tricky way to solve this. If we have to find the number of 4-digit integers that contains at least one 5, we can also find the number of all the 4-digit integers and the number of integers that do not contain any 5's and subtract it from the first number. This is called complementary counting.So, first of all, we must find the number of 4-digit numbers there are. There are 9000 of them.Now, we find the number of 4-digit integers without 5's. By thinking a little bit, we see the first digit must be from 0~9 excluding 5. That is a total of 9 numbers. This is the same for the next three digits. Therefore, there are 94 = 6561 4-digit numbers without a 5.Finally, we can subtract. 9000 - 6561 = 2439
from 1000 to 9999, ie 9999 - 999 = 9000
Let's go through the process: Add 1 to 456: 456 1 = 457 456+1=457 (does not contain the digit 4) Add 2 to 456: 456 2 = 458 456+2=458 (does not contain the digit 4) Add 3 to 456: 456 3 = 459 456+3=459 (does not contain the digit 4) Add 4 to 456: 456 4 = 460 456+4=460 (contains the digit 4) Here, adding 4 gives us 460, which includes the digit 4. Therefore, the smallest number you can add to 456 to get a sum that uses the digit 4 is 4 4 Read More...tinyurl .com/sx3dkfpw