# math

posted by .

Find the mystery number
im a number between 300 and 400
im divisible by 3 and 4 . but not 9
my tens digit is a square number
the sum of the hundreds digit and the tens digit is a prime number.

find the mystery number

• math -

we know that the number is 3xx
the tens digit is either 1,4, or 9
4+3 =7 is a prime, so the number is 34x

x cannot be 2 or 5, because 342 and 345 are divisible by 9 (cast out nines)

The number must be even, because it is divisible by 4. So, it is either

340 344 346 348 (but 4 does not divide 346)

Only 348 is divisible by 3 (cast out threes)

## Similar Questions

1. ### math

This is an SAT question of the day that I can't understand. The sum of the digits of a three-digit number is 12. If the hundreds digit is 3 times the tens digit and the tens digit is 1 over 2 the units digit, what is the tens digit …

i am a 5 digit number my tens digit is the sum of my hundreds digit and thousands digit. my tens digit is twice my ones digit.my hundreds digit is 1 more than zero.my thousands digit is seven times my hundreds digit.my ten thousands …
3. ### math

find the mystery number, it is a 4 digit odd number, all the digits are different, none of the digits are 0-9, the tens digit is twice the ones digit, and the hundreds digit is twice th tens digit. the thousands digit is one less than …

Find the mystery number. It is a 4 digit odd number. All the digits are different. None of the digits are 0 or 9. The tens digit is twice the ones digit, and the hundreds digit is twice the tens digit. The thousands digit is one less …
5. ### Math

It is less than 300. The ones digit is 4 times the hundreds digit. The tens digit is 5 more than the hundreds digit. The sum of the digits is 17. What is the mystery number?
6. ### Math

It is less than 300. The ones digit is 4 times the hundreds digit. The tens digit is 5 more than the hundreds digit. The sum of the digits is 17. What is the mystery number?
7. ### Math

Iam a 5digit number my tens digit is the sum of my hundreds digits and thousands digits my tens digit is twice my ones digit. My hundreds digit is 1more than zero.my thousands digit is seven times my hundreds digit.my ten thousands …
8. ### Math - Algebra

What is the linear equation that will represent the second statement in the following problem: "The sum of the digits of a three-digit number is 12. If the hundreds digit is replaced by the tens digit, the tens digit by the units digit, …
9. ### Algebra - Math HW HELP!

1) It is a five-digit whole number. 2) It is a palindrome. 3) Its tens digit is the cube root of a one-digit number. 4) The product of its hundreds digit and its ones digit is 54. 5) The sum of its hundreds digit and its ones digit …
10. ### thomas middle such

what is the three digit mystery number? if it is less than 300. the tens digit is 5 more than the hundreds digit. the sum if the digits is 11. the hundreds digit is 3 less than the ones digit. the mystery number is

More Similar Questions