Thinking Mathematically (6th Edition)

Published by Pearson
ISBN 10: 0321867327
ISBN 13: 978-0-32186-732-2

Chapter 5 - Number Theory and the Real Number System - 5.1 Number Theory: Prime and Composite Numbers - Exercise Set 5.1: 71

Answer

d = 6

Work Step by Step

Consider 8|76,523,45d when d is equal to 6. For a number to be divisible by 8, its last three digits must make a number divisible by 8. In our case, the last digit (the ones digit) is unknown. The three digit number we use looks like this: 45d, with d being an unknown value. If we substitute each number 0 through 9 for d and then check to see if the number is divisible by 8, we find that only 456 is divisible by 8.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.