Posted by **jessica meyz** on Wednesday, August 5, 2009 at 6:01am.

how many positive four- digit integers have 3 as their tens digit and 5 or 9 as their ones digit?

i dont know where to begin

- Mathematics -
**drwls**, Wednesday, August 5, 2009 at 6:14am
Start listing them. Four-digit numbers must be between 1000 and 9999. The last two numbers must be 35 or 39.

1035

1039

1135

1139

...etc., ending with

9935

9939.

There are 90 pairs of numbers, starting with 10 and ending with 99 as the first two digits.

90 pairs = 180

## Answer this Question

## Related Questions

- Math - How many positive three-digit integers have the property that the tens ...
- math - i am a 4 digit number.my thousands didgit is 4 less than my tens digit.my...
- Algebra - Math HW HELP! - 1) It is a five-digit whole number. 2) It is a ...
- Math (Combinatorics) - How many 4 digit positive integers have the ones digit a ...
- math - i have a six digit question my 100 thousands is one less than my ones ...
- 4th grade - i am a 5 digit number my tens digit is the sum of my hundreds digit ...
- math - My thousands digit is twice my hundreds digit. The sum of my tens and ...
- Math - i am a 4 digit number between 3000 and 4000.My ones digit is twice my ...
- math - my thousand digit is half my ones digit.my houndreds digit is odd and ...
- Math - i am a 4 digit odd number none of the numbers are 0-9 the tens digit is ...

More Related Questions