Friday

October 31, 2014

October 31, 2014

Posted by **Lyndse** on Saturday, September 26, 2009 at 10:23am.

And how many variations of 3_2_ are divisible by six?

- Math -
**MathMate**, Saturday, September 26, 2009 at 6:58pm"True or fals: a number is divisible by 8 if it is divisble by 4 and divisible by 2?"

False.

This logic works if the two numbers are prime to each other, i.e. there are no common factors between the two numbers.

For example, it is true to say that a number is divisible by 6 if it is divisible by 3 and divisible by 2.

If the number 3A2B needs to be divisible by 6 (where A and B stand for undertermined digits), then it has to be divisible by 3 and divisible by 2.

The rule of divisibility for 2 is that the last digit (B) must be even.

The rule of divisibility for 3 is that the sum of all digits must be divisible by 3.

So enumerate the possibilities for A for each possible value of B, as follows:

A=0

B=1 (3120), B=4 (3420) B=7 (3720)

A=2

B=2 (3222), B=5 (3522) B=8 (3822)

A=4

...

A=6

...

A=8

...

How many variations are possible?

**Answer this Question**

**Related Questions**

Math - The question is this: You know that a number is divisible by 6 if it is ...

math - The following conjectures were made by students. Are they true or false? ...

Math PLEASE HELP!!! - Which of the following is false? a. A number that is ...

Math/Algebra - if you add one number divisible by n and one number not divisble ...

Math - Which of the following is false? a. A number that is divisible by 3 and ...

math - Find the value of the missing digit that makes the statement true. 214,...

Math - Use mathematical induction to prove that 5^(n) - 1 is divisible by four ...

teaching math - Indicate whether the deductive reasoning used is an example of ...

teaching math - Indicate whether the deductive reasoning used is an example of ...

math - Indicate whether the deductive reasoning used is an example of affirming ...