What would the code for 13 be in the 1<-3 machine?

a. 20

b. 30

c. 101

d. 111

If you knew the code was 121 in the 1<-3 machine, what was the original number?

a. 16

b. 17

c. 18

d. 19

If you knew the code was 1210 in the 1<-3 machine, what was the original number?

a. 27

b. 33

c. 42

d. 48

We have not talked about a 1<4 machine, but based on what you have seen with the other machines, what would the code for 4 be in this machine?

a. 11

b. 03

c. 10

d. 13

ps. explanation not needed, thanks