Unit 1 Chapter 1 Stage 6 Sending Numbers

CS Principles
1

In the Additional Questions it asks for the minimum number of bits required to send a date in mm/dd format. The answer given is 9 and I keep getting 10. Same with the military time question … answer is 17 and I get 18. One off each time. What am I doing wrong?

Here’s my logic for the mm/dd format:
Throw out the “/”, just consider mmdd
The two options I considered were the dates of 1231 (the largest date with a digit in each position) which in binary is 1 10 11 1, 6 bits.
The other option was 0929. This is the date with the largest digits, taking the most bits. This is 1001 10 1001 in binary, 10 bits.

I cannot logic out the 9 bit answer…

Help and Thanks.

2

Hi Carole,

I think you are representing each digit in the date separately (1, 2, 3, 1). Think about how many bits you might need to represent the month and day each as one number. Based on your example, how many bits would be needed to represent the value 12? Then how many many bits would be needed to represent the value 31?

Hope this helps!
Andrea

3

Ah ha… you are so right!

thanks
Carole