Question

Determine all the following digits that could replace x to make each of the following true.
a. 9∣482x
b. 6|24x35
c. 4|63xx

Answer 1

I believe this symbol has something to do with division, I was taught that d/n meant something like n|d, please help lol

Answer 2

Read 9∣482x as 9 divides 482x. So, we're looking for an x value that makes 482x divisible by 9.
x = 4
If the sum of the digits of the number is divisible by 9, so is the number itself.
482x --> 4+8+2+x ; x = 4 to yield a sum of 9 which is divisible by 9.

Answer 3

b )A number is divisible by 6 if it is divisible by 2 AND it is divisible by 3.

A number is divisible by 2 if the last digit is 0, 2, 4, 6 or 8.
A number is divisible by 3 if the sum of the digits is divisible by 3.

24x35

The mystery number ends in 5. To be divisible by 6, the mystery number has to meet divisibility rules for 2 AND 3.

I think there is no value of x which will make the mystery number divisible by 6.

Answer 4

you are amazing! When I tried figuring b, I also couldn't find a number hence which made me think I was doing it all wrong. How about the last one?

Answer 5

c) Mystery number: 4|63xx
A number is divisible by 4 if the number formed by the last two digits is divisible by 4.

xx must be divisible by 4.

Answer 6

On c) I think there will be multiple answers. So, how about helping me? :) What I'm saying is that I don't know the answer. I'll just apply the divisibility rules and hope for the best and will have your help, of course.

Answer 7

yes, I actually have 00,04, 08, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92 and 96. Thank you so much, I now have some confidence in my answers!

Answer 8

xx means the same digits so of those you have, select--> 00, 44, and 88.

If the mystery number had been 63xy, then all the numbers you listed would have been solutions.

I enjoyed working on this. I hope the answers are right. They look okay to me.

Answer 9

awesome! thank you for pointing that out. I completely overlooked the idea of xx being the same digit! had a nice blonde moment! :)