3.7 Clock Arithmetic
Adding, subtracting, and multiplying on a finite dial where counting wraps around, applied to times, days, and other cyclic quantities.
5 exercises
3.7 Exercise 1
Find the value of the following numbers modulo 12:
- 34
- 539
- 156
3.7 Exercise 3
If it's 3:00, what time will it be in 89 hours?
3.7 Exercise 7
What is the product of 11 and 45 modulo 12?
3.7 Exercise 9
Suppose it is 3:00, and you decide to check your email every 5 hours. What time will it be when you check your email the ninth time?
3.7 Exercise 11
Your family has a cat, and no one wants to empty the litter box. However, it has to be done daily. The six of you agree to take turns, so everyone has to empty the litter box every 6 days. You empty the box on a Thursday. What day will you empty the box for the 10th time?
Adapted from Contemporary Mathematics © 2023 Rice University. Licensed under CC BY 4.0. Source: Contemporary Mathematics. Imported at revision fa7c1a1.