Math
posted by Lyndse .
True or fals: a number is divisible by 8 if it is divisble by 4 and divisible by 2?
And how many variations of 3_2_ are divisible by six?

Math 
MathMate
"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?
Respond to this Question
Similar Questions

Math/Algebra
if you add one number divisible by n and one number not divisble by n will the result be divisible by n? 
Math
The question is this: You know that a number is divisible by 6 if it is divisible by both 3 and 2. So why isn't a number divisible by 8 if it is divisible by both 4 and 2? 
math
The following conjectures were made by students. Are they true or false? 
math
Find the value of the missing digit that makes the statement true. 214,21_ is divisible by 11 Determine whether the statement is true or false. Why? 
Math
Which of the following is false? a. A number that is divisible by 3 and 20 is divisible by 60. b. A number that is divisible by 4 and 15 is divisible by 60. c. A number that is divisible by 5 and 12 is divisible by 60. d. A number 
Math PLEASE HELP!!!
Which of the following is false? a. A number that is divisible by 3 and 20 is divisible by 60. b. A number that is divisible by 4 and 15 is divisible by 60. c. A number that is divisible by 5 and 12 is divisible by 60. d. A number 
number theory
The values A,B,C, and [(A/B)+C], are all integers which are divisible by 3. Then, which of the following statements must be true: A is divisible by 9 B is divisible by 9 C is divisible by 9 A and B are both divisible by 9 A,B,and C … 
maths
The values A,B,C, and [(A/B)+C], are all integers which are divisible by 3. Then, which of the following statements must be true: A is divisible by 9 B is divisible by 9 C is divisible by 9 A and B are both divisible by 9 A,B,and C … 
Mathematics
Can anyone check my answers please True or false 927 is divisible by 3 and 9 true 13,012 is divisible by 9 false 7,434 is divisible by 6 false 2,064 is divisible by 2,4,and8 false 96,240 is divisible by 2,3,5, and 10 false Am I right? 
Mathematics
Can anyone check my answers please True or false 927 is divisible by 3 and 9 true 13,012 is divisible by 9 false 7,434 is divisible by 6 true 2,064 is divisible by 2,4,and8 true 96,240 is divisible by 2,3,5, and 10 true Am I right?