a) baud rate of 10, 20 / 2 bits per change
b) 20

a) baud rate of 100, 300 / 3 bits per change
b) 300

the bit rate is the same as the baudrate when the bitrate is equal to the number of bits per signal change

the baud rate will be higher than the bitrate when the bitrate is lower than the number of bits per signal change